diff --git a/ImperatorToCK3/CK3/Characters/Character.cs b/ImperatorToCK3/CK3/Characters/Character.cs
index 9112d7f9a..3e394e6da 100644
--- a/ImperatorToCK3/CK3/Characters/Character.cs
+++ b/ImperatorToCK3/CK3/Characters/Character.cs
@@ -150,11 +150,11 @@ public string? DeathReason {
 		}
 	}
 
-	public IList<Pregnancy> Pregnancies { get; } = new List<Pregnancy>();
+	public List<Pregnancy> Pregnancies { get; } = [];
 
-	public IDictionary<string, int> MenAtArmsStacksPerType { get; } = new Dictionary<string, int>();
+	public Dictionary<string, int> MenAtArmsStacksPerType { get; } = [];
 
-	public IDictionary<string, string> PrisonerIds { get; } = new Dictionary<string, string>(); // <prisoner id, imprisonment type>
+	public Dictionary<string, string> PrisonerIds { get; } = []; // <prisoner id, imprisonment type>
 
 	internal DNA? DNA { get; set; }
 
diff --git a/ImperatorToCK3/CK3/Cultures/Culture.cs b/ImperatorToCK3/CK3/Cultures/Culture.cs
index 6bc91c65a..7c42d9aa3 100644
--- a/ImperatorToCK3/CK3/Cultures/Culture.cs
+++ b/ImperatorToCK3/CK3/Cultures/Culture.cs
@@ -12,7 +12,7 @@
 
 namespace ImperatorToCK3.CK3.Cultures;
 
-public sealed class Culture : IIdentifiable<string>, IPDXSerializable {
+internal sealed class Culture : IIdentifiable<string>, IPDXSerializable {
 	public string Id { get; }
 	public Color Color { get; }
 	public OrderedSet<string> ParentCultureIds { get; set; }
diff --git a/ImperatorToCK3/CK3/Cultures/CultureData.cs b/ImperatorToCK3/CK3/Cultures/CultureData.cs
index 6b79bdec9..3f86ca12a 100644
--- a/ImperatorToCK3/CK3/Cultures/CultureData.cs
+++ b/ImperatorToCK3/CK3/Cultures/CultureData.cs
@@ -5,8 +5,8 @@
 
 namespace ImperatorToCK3.CK3.Cultures;
 
-public record CultureData {
-	public IEnumerable<string> InvalidatingCultureIds { get; set; } = new List<string>();
+internal record CultureData {
+	public List<string> InvalidatingCultureIds { get; set; } = [];
 	public Color? Color { get; set; }
 	public OrderedSet<string> ParentCultureIds { get; set; } = new();
 	public Pillar? Heritage { get; set; }
@@ -14,5 +14,5 @@ public record CultureData {
 	public OrderedSet<string> TraditionIds { get; set; } = new();
 	public OrderedSet<NameList> NameLists { get; } = new();
 
-	public IList<KeyValuePair<string, StringOfItem>> Attributes { get; } = new List<KeyValuePair<string, StringOfItem>>();
+	public List<KeyValuePair<string, StringOfItem>> Attributes { get; } = [];
 }
\ No newline at end of file
diff --git a/ImperatorToCK3/CK3/Cultures/Pillar.cs b/ImperatorToCK3/CK3/Cultures/Pillar.cs
index 39df08e8a..46979dd93 100644
--- a/ImperatorToCK3/CK3/Cultures/Pillar.cs
+++ b/ImperatorToCK3/CK3/Cultures/Pillar.cs
@@ -7,7 +7,7 @@
 
 namespace ImperatorToCK3.CK3.Cultures; 
 
-public sealed class Pillar : IIdentifiable<string>, IPDXSerializable {
+internal sealed class Pillar : IIdentifiable<string>, IPDXSerializable {
 	public string Id { get; }
 	public string Type { get; }
 	public Color? Color { get; }
diff --git a/ImperatorToCK3/CK3/Cultures/PillarCollection.cs b/ImperatorToCK3/CK3/Cultures/PillarCollection.cs
index a1223e6a2..f21521930 100644
--- a/ImperatorToCK3/CK3/Cultures/PillarCollection.cs
+++ b/ImperatorToCK3/CK3/Cultures/PillarCollection.cs
@@ -9,7 +9,7 @@
 
 namespace ImperatorToCK3.CK3.Cultures; 
 
-public sealed class PillarCollection : IdObjectCollection<string, Pillar> {
+internal sealed class PillarCollection : IdObjectCollection<string, Pillar> {
 	private readonly Dictionary<string, string> mergedPillarsDict = [];
 
 	public PillarCollection(ColorFactory colorFactory, OrderedDictionary<string, bool> ck3ModFlags) {
diff --git a/ImperatorToCK3/CK3/Cultures/PillarData.cs b/ImperatorToCK3/CK3/Cultures/PillarData.cs
index 7b28cbafb..3023181d2 100644
--- a/ImperatorToCK3/CK3/Cultures/PillarData.cs
+++ b/ImperatorToCK3/CK3/Cultures/PillarData.cs
@@ -4,10 +4,10 @@
 
 namespace ImperatorToCK3.CK3.Cultures;
 
-public record PillarData {
-	public IEnumerable<string> InvalidatingPillarIds { get; set; } = new List<string>();
+internal record PillarData {
+	public List<string> InvalidatingPillarIds { get; set; } = [];
 	public string? Type { get; set; }
 	public Color? Color { get; set; }
-	
-	public IList<KeyValuePair<string, StringOfItem>> Attributes { get; } = new List<KeyValuePair<string, StringOfItem>>();
+
+	public List<KeyValuePair<string, StringOfItem>> Attributes { get; } = [];
 }
\ No newline at end of file
diff --git a/ImperatorToCK3/CK3/Religions/FaithData.cs b/ImperatorToCK3/CK3/Religions/FaithData.cs
index 6cf70e882..5403f212f 100644
--- a/ImperatorToCK3/CK3/Religions/FaithData.cs
+++ b/ImperatorToCK3/CK3/Religions/FaithData.cs
@@ -4,12 +4,12 @@
 
 namespace ImperatorToCK3.CK3.Religions; 
 
-public record FaithData {
-	public IEnumerable<string> InvalidatingFaithIds { get; set; } = new List<string>();
+internal record FaithData {
+	public List<string> InvalidatingFaithIds { get; set; } = [];
 	public Color? Color { get; set; }
 	public string? ReligiousHeadTitleId { get; set; }
-	public IList<string> DoctrineIds { get; } = new List<string>();
-	public IList<string> HolySiteIds { get; init; } = new List<string>();
+	public List<string> DoctrineIds { get; } = [];
+	public List<string> HolySiteIds { get; init; } = [];
 
-	public IList<KeyValuePair<string, StringOfItem>> Attributes { get; init; } = new List<KeyValuePair<string, StringOfItem>>();
+	public List<KeyValuePair<string, StringOfItem>> Attributes { get; init; } = [];
 }
\ No newline at end of file
diff --git a/ImperatorToCK3/CK3/Titles/Title.cs b/ImperatorToCK3/CK3/Titles/Title.cs
index 31ddbbc92..fc195305d 100644
--- a/ImperatorToCK3/CK3/Titles/Title.cs
+++ b/ImperatorToCK3/CK3/Titles/Title.cs
@@ -721,9 +721,9 @@ public Date GetDateOfLastHolderChange() {
 		return lastDate ?? new Date(1, 1, 1);
 	}
 
-	public ISet<string> GetAllHolderIds() {
+	public HashSet<string> GetAllHolderIds() {
 		if (!History.Fields.TryGetValue("holder", out var holderField)) {
-			return new HashSet<string>();
+			return [];
 		}
 
 		var ids = new HashSet<string>();
@@ -980,10 +980,10 @@ public void SetDeFactoLiege(Title? newLiege, Date date) {
 
 	private readonly TitleCollection deJureVassals = [];
 	[SerializeOnlyValue] public IReadOnlyTitleCollection DeJureVassals => deJureVassals; // DIRECT de jure vassals
-	public IDictionary<string, Title> GetDeJureVassalsAndBelow() {
+	public Dictionary<string, Title> GetDeJureVassalsAndBelow() {
 		return GetDeJureVassalsAndBelow("bcdke");
 	}
-	public IDictionary<string, Title> GetDeJureVassalsAndBelow(string rankFilter) {
+	public Dictionary<string, Title> GetDeJureVassalsAndBelow(string rankFilter) {
 		var rankFilterAsArray = rankFilter.ToCharArray();
 		Dictionary<string, Title> deJureVassalsAndBelow = new();
 		foreach (var vassalTitle in DeJureVassals) {
@@ -1003,14 +1003,14 @@ public IDictionary<string, Title> GetDeJureVassalsAndBelow(string rankFilter) {
 
 		return deJureVassalsAndBelow;
 	}
-	public IDictionary<string, Title> GetDeFactoVassals(Date date) { // DIRECT de facto vassals
+	public Dictionary<string, Title> GetDeFactoVassals(Date date) { // DIRECT de facto vassals
 		return parentCollection.Where(t => t.GetDeFactoLiege(date)?.Id == Id)
 			.ToDictionary(t => t.Id, t => t);
 	}
-	public IDictionary<string, Title> GetDeFactoVassalsAndBelow(Date date) {
+	public Dictionary<string, Title> GetDeFactoVassalsAndBelow(Date date) {
 		return GetDeFactoVassalsAndBelow(date, "bcdke");
 	}
-	public IDictionary<string, Title> GetDeFactoVassalsAndBelow(Date date, string rankFilter) {
+	public Dictionary<string, Title> GetDeFactoVassalsAndBelow(Date date, string rankFilter) {
 		var rankFilterAsArray = rankFilter.ToCharArray();
 		Dictionary<string, Title> deFactoVassalsAndBelow = new();
 		foreach (var (vassalTitleName, vassalTitle) in GetDeFactoVassals(date)) {
@@ -1052,9 +1052,9 @@ public IDictionary<string, Title> GetDeFactoVassalsAndBelow(Date date, string ra
 	[SerializedName("always_follows_primary_heir")] public bool? AlwaysFollowsPrimaryHeir { get; set; }
 	[SerializedName("de_jure_drift_disabled")] public bool? DeJureDriftDisabled { get; set; }
 	[SerializedName("can_be_named_after_dynasty")] public bool? CanBeNamedAfterDynasty { get; set; }
-	[SerializedName("male_names")] public IList<string>? MaleNames { get; private set; }
+	[SerializedName("male_names")] public List<string>? MaleNames { get; private set; }
 	// <culture, loc key>
-	[SerializedName("cultural_names")] public IDictionary<string, string>? CulturalNames { get; private set; }
+	[SerializedName("cultural_names")] public Dictionary<string, string>? CulturalNames { get; private set; }
 
 	public int? GetOwnOrInheritedDevelopmentLevel(Date date) {
 		var ownDev = GetDevelopmentLevel(date);
@@ -1196,7 +1196,7 @@ public async Task OutputHistory(StreamWriter writer) {
 		await writer.WriteAsync(sb);
 	}
 
-	public ISet<ulong> GetProvincesInCountry(Date date) {
+	public HashSet<ulong> GetProvincesInCountry(Date date) {
 		var holderId = GetHolderId(date);
 		var heldCounties = new List<Title>(
 			parentCollection.Where(t => t.GetHolderId(date) == holderId && t.Rank == TitleRank.county)
diff --git a/ImperatorToCK3/CK3/Wars/War.cs b/ImperatorToCK3/CK3/Wars/War.cs
index 6b02bae8b..303c2640c 100644
--- a/ImperatorToCK3/CK3/Wars/War.cs
+++ b/ImperatorToCK3/CK3/Wars/War.cs
@@ -15,8 +15,8 @@ internal sealed class War {
 	public Date EndDate { get; }
 	public OrderedSet<string> TargetedTitles { get; } = [];
 	public string? CasusBelli { get; }
-	public IList<string> Attackers { get; } = [];
-	public IList<string> Defenders { get; } = [];
+	public List<string> Attackers { get; } = [];
+	public List<string> Defenders { get; } = [];
 	public string Claimant { get; }
 
 	public War(Imperator.Diplomacy.War irWar, Mappers.War.WarMapper warMapper, ProvinceMapper provinceMapper, Imperator.Countries.CountryCollection impCountries, StateCollection irStates, ProvinceCollection ck3Provinces, Title.LandedTitles titles, Date ck3BookmarkDate) {
diff --git a/ImperatorToCK3/CK3/World.cs b/ImperatorToCK3/CK3/World.cs
index 8cea3e062..883b91c1a 100644
--- a/ImperatorToCK3/CK3/World.cs
+++ b/ImperatorToCK3/CK3/World.cs
@@ -56,7 +56,7 @@ internal sealed class World {
 	public ReligionCollection Religions { get; }
 	public IdObjectCollection<string, MenAtArmsType> MenAtArmsTypes { get; } = new();
 	public MapData MapData { get; private set; } = null!;
-	public IList<Wars.War> Wars { get; } = new List<Wars.War>();
+	public List<Wars.War> Wars { get; } = [];
 	public LegendSeedCollection LegendSeeds { get; } = [];
 	internal CoaMapper CK3CoaMapper { get; private set; } = null!;
 	private readonly List<string> enabledDlcFlags = [];
diff --git a/ImperatorToCK3/CommonUtils/Genes/AccessoryGene.cs b/ImperatorToCK3/CommonUtils/Genes/AccessoryGene.cs
index 05e6a0cbd..36001a55e 100644
--- a/ImperatorToCK3/CommonUtils/Genes/AccessoryGene.cs
+++ b/ImperatorToCK3/CommonUtils/Genes/AccessoryGene.cs
@@ -4,7 +4,7 @@
 
 namespace ImperatorToCK3.CommonUtils.Genes;
 
-public sealed class AccessoryGene : Gene, IIdentifiable<string> {
+internal sealed class AccessoryGene : Gene, IIdentifiable<string> {
 	public string Id { get; }
 	public uint? Index { get; private set; }
 	public IdObjectCollection<string, AccessoryGeneTemplate> GeneTemplates { get; } = [];
diff --git a/ImperatorToCK3/CommonUtils/Genes/AccessoryGeneTemplate.cs b/ImperatorToCK3/CommonUtils/Genes/AccessoryGeneTemplate.cs
index 090fd66ed..9891a3be8 100644
--- a/ImperatorToCK3/CommonUtils/Genes/AccessoryGeneTemplate.cs
+++ b/ImperatorToCK3/CommonUtils/Genes/AccessoryGeneTemplate.cs
@@ -4,10 +4,10 @@
 
 namespace ImperatorToCK3.CommonUtils.Genes;
 
-public sealed class AccessoryGeneTemplate : IIdentifiable<string> {
+internal sealed class AccessoryGeneTemplate : IIdentifiable<string> {
 	public string Id { get; }
 	public uint Index { get; private set; } = 0;
-	public IDictionary<string, WeightBlock> AgeSexWeightBlocks { get; } = new Dictionary<string, WeightBlock>();
+	public Dictionary<string, WeightBlock> AgeSexWeightBlocks { get; } = [];
 
 	public AccessoryGeneTemplate(string id, BufferedReader reader) {
 		Id = id;
diff --git a/ImperatorToCK3/CommonUtils/Genes/GenesDB.cs b/ImperatorToCK3/CommonUtils/Genes/GenesDB.cs
index b8e992bb7..de9db447c 100644
--- a/ImperatorToCK3/CommonUtils/Genes/GenesDB.cs
+++ b/ImperatorToCK3/CommonUtils/Genes/GenesDB.cs
@@ -4,7 +4,7 @@
 
 namespace ImperatorToCK3.CommonUtils.Genes;
 
-public sealed class GenesDB {
+internal sealed class GenesDB {
 	public IdObjectCollection<string, AccessoryGene> AccessoryGenes { get; } = new();
 	public IdObjectCollection<string, MorphGene> MorphGenes { get; } = new();
 	public IdObjectCollection<string, AccessoryGene> SpecialAccessoryGenes { get; } = new();
diff --git a/ImperatorToCK3/CommonUtils/Map/MapData.cs b/ImperatorToCK3/CommonUtils/Map/MapData.cs
index 9bc83a846..d46bd7f61 100644
--- a/ImperatorToCK3/CommonUtils/Map/MapData.cs
+++ b/ImperatorToCK3/CommonUtils/Map/MapData.cs
@@ -11,7 +11,7 @@
 
 namespace ImperatorToCK3.CommonUtils.Map;
 
-public sealed class MapData {
+internal sealed class MapData {
 	[StructLayout(LayoutKind.Auto)]
 	private struct Point(int x, int y) : IEquatable<Point> {
 		public int X { get; set; } = x;
diff --git a/ImperatorToCK3/CommonUtils/Map/ProvinceDefinitions.cs b/ImperatorToCK3/CommonUtils/Map/ProvinceDefinitions.cs
index 77aac5f34..7d03072c6 100644
--- a/ImperatorToCK3/CommonUtils/Map/ProvinceDefinitions.cs
+++ b/ImperatorToCK3/CommonUtils/Map/ProvinceDefinitions.cs
@@ -8,8 +8,8 @@
 
 namespace ImperatorToCK3.CommonUtils.Map;
 
-public sealed class ProvinceDefinitions : IdObjectCollection<ulong, ProvinceDefinition> {
-	public IDictionary<Rgb24, ulong> ColorToProvinceDict { get; } = new Dictionary<Rgb24, ulong>();
+internal sealed class ProvinceDefinitions : IdObjectCollection<ulong, ProvinceDefinition> {
+	public Dictionary<Rgb24, ulong> ColorToProvinceDict { get; } = [];
 	public Dictionary<ulong, Rgb24> ProvinceToColorDict { get; } = [];
 
 	public void LoadDefinitions(string definitionsFilename, ModFilesystem modFS) {
diff --git a/ImperatorToCK3/Imperator/Characters/Character.cs b/ImperatorToCK3/Imperator/Characters/Character.cs
index efed58f41..22a924beb 100644
--- a/ImperatorToCK3/Imperator/Characters/Character.cs
+++ b/ImperatorToCK3/Imperator/Characters/Character.cs
@@ -65,11 +65,11 @@ public bool LinkFamily(FamilyCollection families, SortedSet<ulong>? missingDefin
 	public bool IsDead => DeathDate is not null;
 	public string? DeathReason { get; set; }
 	private HashSet<ulong> parsedSpouseIds = [];
-	public IDictionary<ulong, Character> Spouses { get; set; } = new Dictionary<ulong, Character>();
+	public Dictionary<ulong, Character> Spouses { get; set; } = [];
 	public OrderedSet<ulong> FriendIds { get; } = [];
 	public OrderedSet<ulong> RivalIds { get; } = [];
 	private HashSet<ulong> parsedChildrenIds = [];
-	public IDictionary<ulong, Character> Children { get; set; } = new Dictionary<ulong, Character>();
+	public Dictionary<ulong, Character> Children { get; set; } = [];
 	private ulong? parsedMotherId;
 	public Character? Mother { get; set; }
 	private ulong? parsedFatherId;
@@ -88,7 +88,7 @@ public Family? Family {
 		}
 	}
 
-	public IList<string> Traits { get; set; } = [];
+	public List<string> Traits { get; set; } = [];
 	public CharacterAttributes Attributes { get; private set; } = new();
 	public IReadOnlySet<string> Variables { get; private set; } = ImmutableHashSet<string>.Empty;
 	public bool IsBald => Variables.Contains("bald");
diff --git a/ImperatorToCK3/Imperator/Characters/PortraitData.cs b/ImperatorToCK3/Imperator/Characters/PortraitData.cs
index dead38833..82ef1d7d0 100644
--- a/ImperatorToCK3/Imperator/Characters/PortraitData.cs
+++ b/ImperatorToCK3/Imperator/Characters/PortraitData.cs
@@ -6,7 +6,7 @@
 
 namespace ImperatorToCK3.Imperator.Characters; 
 
-public sealed class PortraitData {
+internal sealed class PortraitData {
 	public PaletteCoordinates HairColorPaletteCoordinates { get; } = new();
 	public PaletteCoordinates HairColor2PaletteCoordinates { get; } = new();
 	public PaletteCoordinates SkinColorPaletteCoordinates { get; } = new();
@@ -14,9 +14,8 @@ public sealed class PortraitData {
 	public PaletteCoordinates EyeColorPaletteCoordinates { get; } = new();
 	public PaletteCoordinates EyeColor2PaletteCoordinates { get; } = new();
 
-	public IDictionary<string, AccessoryGeneData> AccessoryGenesDict { get; } =
-		new Dictionary<string, AccessoryGeneData>();
-	public IDictionary<string, MorphGeneData> MorphGenesDict { get; } = new Dictionary<string, MorphGeneData>();
+	public Dictionary<string, AccessoryGeneData> AccessoryGenesDict { get; } = [];
+	public Dictionary<string, MorphGeneData> MorphGenesDict { get; } = [];
 
 	public PortraitData(string dnaString, GenesDB genesDB, string ageSexString = "male") {
 		var decodedDnaStr = Convert.FromBase64String(dnaString);
diff --git a/ImperatorToCK3/Imperator/Diplomacy/DiplomacyDB.cs b/ImperatorToCK3/Imperator/Diplomacy/DiplomacyDB.cs
index 159988479..5718f10a4 100644
--- a/ImperatorToCK3/Imperator/Diplomacy/DiplomacyDB.cs
+++ b/ImperatorToCK3/Imperator/Diplomacy/DiplomacyDB.cs
@@ -5,7 +5,7 @@
 
 namespace ImperatorToCK3.Imperator.Diplomacy;
 
-public sealed class DiplomacyDB {
+internal sealed class DiplomacyDB {
 	private readonly List<War> wars = [];
 	public IReadOnlyList<War> Wars => wars;
 	
diff --git a/ImperatorToCK3/Imperator/Diplomacy/War.cs b/ImperatorToCK3/Imperator/Diplomacy/War.cs
index c202a1cf8..a20202f8a 100644
--- a/ImperatorToCK3/Imperator/Diplomacy/War.cs
+++ b/ImperatorToCK3/Imperator/Diplomacy/War.cs
@@ -4,11 +4,11 @@
 
 namespace ImperatorToCK3.Imperator.Diplomacy;
 
-public sealed class War {
+internal sealed class War {
 	public Date StartDate { get; private set; } = new(1, 1, 1);
 	public bool Previous { get; private set; }
-	public IList<ulong> AttackerCountryIds { get; } = new List<ulong>();
-	public IList<ulong> DefenderCountryIds { get; } = new List<ulong>();
+	public List<ulong> AttackerCountryIds { get; } = [];
+	public List<ulong> DefenderCountryIds { get; } = [];
 	public string? WarGoal { get; private set; }
 	public ulong? TargetedStateId { get; private set; }
 
diff --git a/ImperatorToCK3/Imperator/Jobs/JobsDB.cs b/ImperatorToCK3/Imperator/Jobs/JobsDB.cs
index 27652b967..7bf4099c1 100644
--- a/ImperatorToCK3/Imperator/Jobs/JobsDB.cs
+++ b/ImperatorToCK3/Imperator/Jobs/JobsDB.cs
@@ -9,8 +9,8 @@
 namespace ImperatorToCK3.Imperator.Jobs;
 
 internal sealed class JobsDB {
-	public IList<Governorship> Governorships { get; } = [];
-	public IList<OfficeJob> OfficeJobs { get; } = [];
+	public List<Governorship> Governorships { get; } = [];
+	public List<OfficeJob> OfficeJobs { get; } = [];
 
 	public JobsDB() { }
 	public JobsDB(BufferedReader jobsReader, CharacterCollection characters, CountryCollection countries, ImperatorRegionMapper irRegionMapper) {
diff --git a/ImperatorToCK3/Imperator/Provinces/Province.cs b/ImperatorToCK3/Imperator/Provinces/Province.cs
index 8bd33da66..2e12f8251 100644
--- a/ImperatorToCK3/Imperator/Provinces/Province.cs
+++ b/ImperatorToCK3/Imperator/Provinces/Province.cs
@@ -17,7 +17,7 @@ internal sealed partial class Province : IIdentifiable<ulong> {
 	public State? State { get; private set; } = null;
 	public Country? OwnerCountry { get; set; }
 	public ulong Controller { get; set; } = 0;
-	public IDictionary<ulong, Pop> Pops { get; } = new Dictionary<ulong, Pop>();
+	public Dictionary<ulong, Pop> Pops { get; } = [];
 	public ProvinceRank ProvinceRank { get; set; } = ProvinceRank.settlement;
 	public bool Fort { get; set; } = false;
 	public bool IsHolySite => HolySiteId is not null;
diff --git a/ImperatorToCK3/Mappers/Gene/AccessoryGeneMapper.cs b/ImperatorToCK3/Mappers/Gene/AccessoryGeneMapper.cs
index 4dd5165ca..758f82d95 100644
--- a/ImperatorToCK3/Mappers/Gene/AccessoryGeneMapper.cs
+++ b/ImperatorToCK3/Mappers/Gene/AccessoryGeneMapper.cs
@@ -6,8 +6,8 @@
 namespace ImperatorToCK3.Mappers.Gene; 
 
 public sealed class AccessoryGeneMapper {
-	private Dictionary<string, IList<Assignment>> ObjectToObjectMappings { get; } = [];
-	private Dictionary<string, IList<Assignment>> TemplateToTemplateMappings { get; } = [];
+	private Dictionary<string, List<Assignment>> ObjectToObjectMappings { get; } = [];
+	private Dictionary<string, List<Assignment>> TemplateToTemplateMappings { get; } = [];
 
 	public AccessoryGeneMapper(string mappingsFilePath) {
 		var objectToObjectMappingsParser = new Parser();
diff --git a/ImperatorToCK3/Mappers/Province/ProvinceMapper.cs b/ImperatorToCK3/Mappers/Province/ProvinceMapper.cs
index c33a33bb3..d4bc88400 100644
--- a/ImperatorToCK3/Mappers/Province/ProvinceMapper.cs
+++ b/ImperatorToCK3/Mappers/Province/ProvinceMapper.cs
@@ -4,9 +4,9 @@
 
 namespace ImperatorToCK3.Mappers.Province;
 
-public sealed class ProvinceMapper {
-	private readonly Dictionary<ulong, IList<ulong>> imperatorToCK3ProvinceMap = new();
-	private readonly Dictionary<ulong, IList<ulong>> ck3ToImperatorProvinceMap = new();
+internal sealed class ProvinceMapper {
+	private readonly Dictionary<ulong, List<ulong>> imperatorToCK3ProvinceMap = [];
+	private readonly Dictionary<ulong, List<ulong>> ck3ToImperatorProvinceMap = [];
 
 	public void LoadMappings(string mappingsPath) {
 		Logger.Info("Loading province mappings...");
@@ -50,17 +50,17 @@ private void CreateMappings(ProvinceMappingsVersion mappingsVersion) {
 		}
 	}
 
-	public IList<ulong> GetImperatorProvinceNumbers(ulong ck3ProvinceNumber) {
+	public List<ulong> GetImperatorProvinceNumbers(ulong ck3ProvinceNumber) {
 		if (ck3ToImperatorProvinceMap.TryGetValue(ck3ProvinceNumber, out var impProvs)) {
 			return impProvs;
 		}
-		return new List<ulong>();
+		return [];
 	}
 
-	public IList<ulong> GetCK3ProvinceNumbers(ulong impProvinceNumber) {
+	public List<ulong> GetCK3ProvinceNumbers(ulong impProvinceNumber) {
 		if (imperatorToCK3ProvinceMap.TryGetValue(impProvinceNumber, out var ck3Provs)) {
 			return ck3Provs;
 		}
-		return new List<ulong>();
+		return [];
 	}
 }
\ No newline at end of file
diff --git a/ImperatorToCK3/Mappers/Province/ProvinceMapping.cs b/ImperatorToCK3/Mappers/Province/ProvinceMapping.cs
index 9a8cbcf49..45a72fb2e 100644
--- a/ImperatorToCK3/Mappers/Province/ProvinceMapping.cs
+++ b/ImperatorToCK3/Mappers/Province/ProvinceMapping.cs
@@ -4,8 +4,8 @@
 namespace ImperatorToCK3.Mappers.Province;
 
 internal sealed class ProvinceMapping {
-	public IList<ulong> CK3Provinces { get; } = new List<ulong>();
-	public IList<ulong> ImperatorProvinces { get; } = new List<ulong>();
+	public List<ulong> CK3Provinces { get; } = [];
+	public List<ulong> ImperatorProvinces { get; } = [];
 
 	private static readonly Parser parser = new();
 	private static ProvinceMapping tempMapping = new();
diff --git a/ImperatorToCK3/Mappers/Province/ProvinceMappingsVersion.cs b/ImperatorToCK3/Mappers/Province/ProvinceMappingsVersion.cs
index 15aae8ee0..e3ececff0 100644
--- a/ImperatorToCK3/Mappers/Province/ProvinceMappingsVersion.cs
+++ b/ImperatorToCK3/Mappers/Province/ProvinceMappingsVersion.cs
@@ -5,7 +5,7 @@
 namespace ImperatorToCK3.Mappers.Province;
 
 internal sealed class ProvinceMappingsVersion {
-	public IList<ProvinceMapping> Mappings { get; } = [];
+	public List<ProvinceMapping> Mappings { get; } = [];
 	public ProvinceMappingsVersion() { }
 	public ProvinceMappingsVersion(BufferedReader reader) {
 		var referencedImperatorProvs = new HashSet<ulong>();
diff --git a/ImperatorToCK3/Mappers/Technology/InnovationMapper.cs b/ImperatorToCK3/Mappers/Technology/InnovationMapper.cs
index 36add7ff8..cffff186f 100644
--- a/ImperatorToCK3/Mappers/Technology/InnovationMapper.cs
+++ b/ImperatorToCK3/Mappers/Technology/InnovationMapper.cs
@@ -6,7 +6,7 @@
 
 namespace ImperatorToCK3.Mappers.Technology;
 
-public sealed class InnovationMapper {
+internal sealed class InnovationMapper {
 	private readonly List<InnovationLink> innovationLinks = [];
 	private readonly List<InnovationBonus> innovationBonuses = [];
 
@@ -18,7 +18,7 @@ public void LoadLinksAndBonuses(string configurablePath) {
 		parser.ParseFile(configurablePath);
 	}
 
-	public IList<string> GetInnovations(IEnumerable<string> irInventions) {
+	public List<string> GetInnovations(IEnumerable<string> irInventions) {
 		var ck3Innovations = new List<string>();
 		foreach (var irInvention in irInventions) {
 			foreach (var link in innovationLinks) {
@@ -31,7 +31,7 @@ public IList<string> GetInnovations(IEnumerable<string> irInventions) {
 		return ck3Innovations;
 	}
 
-	public IDictionary<string, ushort> GetInnovationProgresses(ICollection<string> irInventions) {
+	public Dictionary<string, ushort> GetInnovationProgresses(ICollection<string> irInventions) {
 		Dictionary<string, ushort> progressesToReturn = [];
 		foreach (var bonus in innovationBonuses) {
 			var innovationProgress = bonus.GetProgress(irInventions);
diff --git a/ImperatorToCK3/Outputter/PillarOutputter.cs b/ImperatorToCK3/Outputter/PillarOutputter.cs
index 458a89e5c..3b2a18eca 100644
--- a/ImperatorToCK3/Outputter/PillarOutputter.cs
+++ b/ImperatorToCK3/Outputter/PillarOutputter.cs
@@ -7,7 +7,7 @@
 
 namespace ImperatorToCK3.Outputter;
 
-public static class PillarOutputter {
+internal static class PillarOutputter {
 	public static async Task OutputPillars(string outputPath, PillarCollection pillars) {
 		Logger.Info("Outputting pillars...");