diff --git a/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8N.cs b/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8N.cs
index 2fcd5d8bc..62e6a73ce 100644
--- a/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8N.cs
+++ b/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8N.cs
@@ -160,7 +160,7 @@ private static byte GetInitialDynamaxLevel(Xoroshiro128Plus rand, int rank)
         return (byte)(baseValue + boost);
     }
 
-    public override void GenerateSeed64(PKM pk, ulong seed)
+    public override void GenerateSeed64(PKM pk, ITrainerInfo tr, ulong seed)
     {
         var (_, noShiny) = IsPossibleSeed(pk, seed, false);
         var param = GetParam();
diff --git a/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8Nest.cs b/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8Nest.cs
index f84692db8..85c64a958 100644
--- a/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8Nest.cs
+++ b/PKHeX.Core/Legality/Encounters/Templates/Gen8/EncounterStatic8Nest.cs
@@ -253,7 +253,7 @@ public bool Verify(PKM pk, ulong seed, bool forceNoShiny = false)
         return RaidRNG.Verify(pk, seed, iv, param, forceNoShiny: forceNoShiny);
     }
 
-    public virtual void GenerateSeed64(PKM pk, ulong seed)
+    public virtual void GenerateSeed64(PKM pk, ITrainerInfo tr, ulong seed)
     {
         var criteria = EncounterCriteria.Unrestricted;
         var pk8 = (PK8)pk;
diff --git a/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterSlot8a.cs b/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterSlot8a.cs
index 434a8e1ba..1aa09af52 100644
--- a/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterSlot8a.cs
+++ b/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterSlot8a.cs
@@ -56,7 +56,7 @@ public PA8 ConvertToPKM(ITrainerInfo tr, EncounterCriteria criteria)
             OriginalTrainerFriendship = pi.BaseFriendship,
             Nickname = SpeciesName.GetSpeciesNameGeneration(Species, language, Generation),
         };
-        SetPINGA(pk, criteria, pi);
+        SetPINGA(pk, tr, criteria, pi);
         pk.Scale = pk.HeightScalar;
         pk.ResetHeight();
         pk.ResetWeight();
@@ -65,9 +65,10 @@ public PA8 ConvertToPKM(ITrainerInfo tr, EncounterCriteria criteria)
         return pk;
     }
 
-    private void SetPINGA(PA8 pk, in EncounterCriteria criteria, PersonalInfo8LA pi)
+    private void SetPINGA(PA8 pk, ITrainerInfo tr, in EncounterCriteria criteria, PersonalInfo8LA pi)
     {
-        var para = GetParams(pi);
+        var rollCount = GetRollCount(Type, tr);
+        var para = GetParams(pi, rollCount);
         bool checkLevel = criteria.IsSpecifiedLevelRange() && this.IsLevelWithinRange(criteria);
         while (true)
         {
@@ -84,22 +85,23 @@ private void SetPINGA(PA8 pk, in EncounterCriteria criteria, PersonalInfo8LA pi)
         }
     }
 
-    public void GenerateSeed64(PKM pk, ulong seed)
+    public void GenerateSeed64(PKM pk, ITrainerInfo tr, ulong seed)
     {
         if (pk is not PA8 pa8)
             throw new ArgumentException($"{nameof(pk)} must be a {nameof(PA8)} instance.", nameof(pk));
         var criteria = EncounterCriteria.Unrestricted;
         var pi = PersonalTable.LA.GetFormEntry(Species, Form);
-        var para = GetParams(pi);
+        var rollCount = GetRollCount(Type, tr);
+        var para = GetParams(pi, rollCount);
         _ = Overworld8aRNG.ApplyDetails(pa8, criteria, para, HasAlphaMove);
     }
 
-    private OverworldParam8a GetParams(PersonalInfo8LA pi) => new()
+    private OverworldParam8a GetParams(PersonalInfo8LA pi, byte rollCount) => new()
     {
         Shiny = Shiny,
         IsAlpha = IsAlpha,
         FlawlessIVs = FlawlessIVCount,
-        RollCount = GetRollCount(Type),
+        RollCount = rollCount,
         GenderRatio = Gender switch
         {
             Gender.Male => PersonalInfo.RatioMagicMale,
@@ -111,12 +113,21 @@ private OverworldParam8a GetParams(PersonalInfo8LA pi) => new()
     // hardcoded 7 to assume max dex progress + shiny charm.
     private const int MaxRollCount = 7;
 
-    private static byte GetRollCount(SlotType8a type) => (byte)(MaxRollCount + type switch
+    private byte GetRollCount(SlotType8a type, ITrainerInfo tr) => (byte)(GetRollCountBase(tr, Species) + GetRollCountBoost(type));
+
+    private static byte GetRollCountBoost(SlotType8a type) => type switch
     {
         SlotType8a.MassOutbreakMassive => 12,
         SlotType8a.MassOutbreakRegular => 25,
         _ => 0,
-    });
+    };
+
+    private int GetRollCountBase(ITrainerInfo tr, ushort species)
+    {
+        if (tr is not ITrainerInfo8a la)
+            return MaxRollCount;
+        return la.GetShinyRolls(species);
+    }
 
     private void SetEncounterMoves(PA8 pk, byte level)
     {
@@ -246,7 +257,8 @@ public SeedCorrelationResult TryGetSeed(PKM pk, out ulong seed)
     {
         // Check if it matches any single-roll seed.
         var pi = PersonalTable.LA[Species, Form];
-        var param = GetParams(pi) with { RollCount = 1 };
+        var rollCount = (byte)(1 + GetRollCountBoost(Type));
+        var param = GetParams(pi, rollCount);
         var solver = new XoroMachineSkip(pk.EncryptionConstant, pk.PID);
         foreach (var s in solver)
         {
diff --git a/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterStatic8a.cs b/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterStatic8a.cs
index a298c94d2..7c6594662 100644
--- a/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterStatic8a.cs
+++ b/PKHeX.Core/Legality/Encounters/Templates/Gen8a/EncounterStatic8a.cs
@@ -118,7 +118,7 @@ private void Finalize(PA8 pk, ulong slotSeed)
         SetEncounterMoves(pk, pk.MetLevel);
     }
 
-    public void GenerateSeed64(PKM pk, ulong seed)
+    public void GenerateSeed64(PKM pk, ITrainerInfo tr, ulong seed)
     {
         var pa8 = (PA8)pk;
         var criteria = EncounterCriteria.Unrestricted;
diff --git a/PKHeX.Core/Legality/Encounters/Templates/Interfaces/RNG/IGenerateSeed64.cs b/PKHeX.Core/Legality/Encounters/Templates/Interfaces/RNG/IGenerateSeed64.cs
index 2ccf9b6e6..505af6b18 100644
--- a/PKHeX.Core/Legality/Encounters/Templates/Interfaces/RNG/IGenerateSeed64.cs
+++ b/PKHeX.Core/Legality/Encounters/Templates/Interfaces/RNG/IGenerateSeed64.cs
@@ -9,5 +9,5 @@ public interface IGenerateSeed64
     /// Generates the <see cref="PKM"/> from the seed.
     /// </summary>
     /// <remarks>Be sure the <see cref="pk"/> is un-converted and matches its original type.</remarks>
-    void GenerateSeed64(PKM pk, ulong seed);
+    void GenerateSeed64(PKM pk, ITrainerInfo tr, ulong seed);
 }
diff --git a/PKHeX.Core/Legality/RNG/ClassicEra/Gen4/MethodK.cs b/PKHeX.Core/Legality/RNG/ClassicEra/Gen4/MethodK.cs
index 385ec176e..48ad82243 100644
--- a/PKHeX.Core/Legality/RNG/ClassicEra/Gen4/MethodK.cs
+++ b/PKHeX.Core/Legality/RNG/ClassicEra/Gen4/MethodK.cs
@@ -284,7 +284,7 @@ private static bool TryGetMatch<T>(in SearchContext<T> ctx, uint seed, byte natu
     }
 
     /// <summary>
-    /// Represents the magic number that that allows any lead to be used, enabling the generation target to require or not require a synchronize lead.
+    /// Represents the magic number that allows any lead to be used, enabling the generation target to require or not require a synchronize lead.
     /// </summary>
     private const Nature LeadSyncAllowed = Nature.Random;
 
diff --git a/PKHeX.Core/Saves/Abstractions/ITrainerInfo.cs b/PKHeX.Core/Saves/Abstractions/ITrainerInfo.cs
index 53747dcdb..1bbfa7f65 100644
--- a/PKHeX.Core/Saves/Abstractions/ITrainerInfo.cs
+++ b/PKHeX.Core/Saves/Abstractions/ITrainerInfo.cs
@@ -137,3 +137,15 @@ private static bool IsMatchVersion(ITrainerInfo tr, PKM pk)
         return false;
     }
 }
+
+/// <summary>
+/// Save File specific interface for trainer objects to expose information about how many shiny rolls a species may be generated with.
+/// </summary>
+/// <remarks>
+/// Currently only useful for <see cref="GameVersion.PLA"/> which ties Pokédex progress to shiny rolls.
+/// By implementing this interface, a generated Pokémon can be generated more plausibly, and the save file can quickly inform.
+/// </remarks>
+public interface ITrainerInfo8a
+{
+    byte GetShinyRolls(ushort species);
+}
diff --git a/PKHeX.Core/Saves/SAV8LA.cs b/PKHeX.Core/Saves/SAV8LA.cs
index 2a94528d3..74e364632 100644
--- a/PKHeX.Core/Saves/SAV8LA.cs
+++ b/PKHeX.Core/Saves/SAV8LA.cs
@@ -6,7 +6,7 @@ namespace PKHeX.Core;
 /// <summary>
 /// Generation 8 <see cref="SaveFile"/> object for <see cref="GameVersion.PLA"/> games.
 /// </summary>
-public sealed class SAV8LA : SaveFile, ISaveBlock8LA, ISCBlockArray, ISaveFileRevision, IBoxDetailName, IBoxDetailWallpaper
+public sealed class SAV8LA : SaveFile, ISaveBlock8LA, ISCBlockArray, ISaveFileRevision, IBoxDetailName, IBoxDetailWallpaper, ITrainerInfo8a
 {
     protected internal override string ShortSummary => $"{OT} ({Version}) - {LastSaved.DisplayValue}";
     public override string Extension => string.Empty;
@@ -136,6 +136,33 @@ protected override SAV8LA CloneInternal()
     protected override Span<byte> PartyBuffer => PartyInfo.Data;
 
     public override bool HasPokeDex => true;
+
+    public byte GetShinyRolls(ushort species)
+    {
+        // Level 10: +1
+        // Perfect: +2
+        // Shiny Charm: +3
+
+        var dex = PokedexSave;
+        byte rolls = HasKeyItem(632) ? (byte)(1 + 3) : (byte)1;
+        if (!dex.IsComplete(species))
+            return rolls;
+        if (!dex.IsPerfect(species))
+            return (byte)(rolls + 1);
+        return (byte)(rolls + 3);
+    }
+
+    private bool HasKeyItem(ushort item)
+    {
+        var span = Accessor.GetBlock(SaveBlockAccessor8LA.KItemKey).Data;
+        // Look for (u16 632, u16 1) after reinterpreting as u32, respecting endianness as Little Endian
+        var cast = System.Runtime.InteropServices.MemoryMarshal.Cast<byte, uint>(span);
+        var seek = (uint)(item | (1 << 16)); // 0x00010278
+        if (!BitConverter.IsLittleEndian)
+            seek = System.Buffers.Binary.BinaryPrimitives.ReverseEndianness(seek);
+        return cast.Contains(seek);
+    }
+
     private void Initialize()
     {
         Box = 0;
diff --git a/PKHeX.Core/Saves/Substructures/Inventory/Item/InventoryItem8a.cs b/PKHeX.Core/Saves/Substructures/Inventory/Item/InventoryItem8a.cs
index d3f642de8..445d54d1e 100644
--- a/PKHeX.Core/Saves/Substructures/Inventory/Item/InventoryItem8a.cs
+++ b/PKHeX.Core/Saves/Substructures/Inventory/Item/InventoryItem8a.cs
@@ -8,7 +8,7 @@ public sealed record InventoryItem8a : InventoryItem, IItemFavorite
     public const int SIZE = 0x10;
 
     public override string ToString() => $"{Index:000} x{Count}";
-    public bool IsFavorite { get; set; }
+    public bool IsFavorite { get; set; } // favorites stored separately, this is just a fake property mirror
 
     public override void Clear()
     {
@@ -23,7 +23,7 @@ public static InventoryItem8a Read(ReadOnlySpan<byte> data) => new()
 
     public void Write(Span<byte> data)
     {
-        // Index is not saved.
+        // Favorite is saved separately.
         WriteUInt16LittleEndian(data, (ushort)Index);
         WriteUInt16LittleEndian(data[2..], (ushort)Count);
     }