diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7a8dc56..e85119a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -90,7 +90,9 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v3
         with:
-          dotnet-version: '7.0'
+          dotnet-version: |
+            7.0
+            8.0
 
       - name: Download Dalamud
         run: |
diff --git a/Benchmark/Bench.cs b/Benchmark/Bench.cs
index 2518195..8485503 100644
--- a/Benchmark/Bench.cs
+++ b/Benchmark/Bench.cs
@@ -1,15 +1,27 @@
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Diagnostics.dotTrace;
+using BenchmarkDotNet.Jobs;
 using Craftimizer.Simulator;
 using Craftimizer.Solver;
+using System.Security.Cryptography;
+using System.Text;
 
 namespace Craftimizer.Benchmark;
 
-[SimpleJob(iterationCount: 10)]
+[SimpleJob(RuntimeMoniker.Net70, baseline: true)]
+[SimpleJob(RuntimeMoniker.Net80)]
 [MinColumn, Q1Column, Q3Column, MaxColumn]
 [DotTraceDiagnoser]
 public class Bench
 {
+    public record struct SHAWrapper<T>(T Data) where T : notnull
+    {
+        public static implicit operator T(SHAWrapper<T> wrapper) => wrapper.Data;
+
+        public override readonly string ToString() =>
+            Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(Data.ToString()!)));
+    }
+
     private static SimulationInput[] Inputs { get; } = new SimulationInput[] {
         // https://craftingway.app/rotation/loud-namazu-jVe9Y
         // Chondrite Saw
@@ -68,22 +80,22 @@ public class Bench
         })
     };
 
-    public static IEnumerable<SimulationState> States => Inputs.Select(i => new SimulationState(i));
+    public static IEnumerable<SHAWrapper<SimulationState>> States => Inputs.Select(i => new SHAWrapper<SimulationState>(new(i)));
 
-    public static IEnumerable<SolverConfig> Configs => new SolverConfig[]
+    public static IEnumerable<SHAWrapper<SolverConfig>> Configs => new SHAWrapper<SolverConfig>[]
     {
-        new()
+        new(new()
         {
             Algorithm = SolverAlgorithm.Stepwise,
             Iterations = 30_000,
-        }
+        })
     };
 
     [ParamsSource(nameof(States))]
-    public SimulationState State { get; set; }
+    public SHAWrapper<SimulationState> State { get; set; }
 
     [ParamsSource(nameof(Configs))]
-    public SolverConfig Config { get; set; }
+    public SHAWrapper<SolverConfig> Config { get; set; }
 
     [Benchmark]
     public async Task<float> Solve()
diff --git a/Benchmark/Program.cs b/Benchmark/Program.cs
index 70c6299..4ba614e 100644
--- a/Benchmark/Program.cs
+++ b/Benchmark/Program.cs
@@ -1,6 +1,7 @@
 using Craftimizer.Simulator;
 using Craftimizer.Simulator.Actions;
 using Craftimizer.Solver;
+using ObjectLayoutInspector;
 
 namespace Craftimizer.Benchmark;
 
@@ -63,8 +64,11 @@ private static async Task RunTrace()
 
     private static async Task RunOther()
     {
-        //TypeLayout.PrintLayout<ArenaNode<SimulationNode>>(true);
-        //return;
+        TypeLayout.PrintLayout<SimulationState>(true);
+        TypeLayout.PrintLayout<Simulator.Simulator>(true);
+        TypeLayout.PrintLayout<BaseAction>(true);
+        TypeLayout.PrintLayout<SimulationNode>(true);
+        return;
 
         var input = new SimulationInput(
             new CharacterStats
diff --git a/Simulator/Actions/BaseComboAction.cs b/Simulator/Actions/BaseComboAction.cs
index 80d11f7..16876c5 100644
--- a/Simulator/Actions/BaseComboAction.cs
+++ b/Simulator/Actions/BaseComboAction.cs
@@ -10,7 +10,7 @@ public abstract class BaseComboAction : BaseAction
     protected bool BaseCanUse(Simulator s) =>
         base.CanUse(s);
 
-    private static bool VerifyDurability2(int durabilityA, int durability, Effects effects)
+    private static bool VerifyDurability2(int durabilityA, int durability, in Effects effects)
     {
         var wasteNots = effects.HasEffect(EffectType.WasteNot) || effects.HasEffect(EffectType.WasteNot2);
         // -A
@@ -23,13 +23,10 @@ private static bool VerifyDurability2(int durabilityA, int durability, Effects e
         return true;
     }
 
-    public static bool VerifyDurability2(SimulationState s, int durabilityA) =>
-        VerifyDurability2(durabilityA, s.Durability, s.ActiveEffects);
-
     public static bool VerifyDurability2(Simulator s, int durabilityA) =>
         VerifyDurability2(durabilityA, s.Durability, s.ActiveEffects);
 
-    public static bool VerifyDurability3(int durabilityA, int durabilityB, int durability, Effects effects)
+    public static bool VerifyDurability3(int durabilityA, int durabilityB, int durability, in Effects effects)
     {
         var wasteNots = Math.Max(effects.GetDuration(EffectType.WasteNot), effects.GetDuration(EffectType.WasteNot2));
         var manips = effects.HasEffect(EffectType.Manipulation);
@@ -56,7 +53,4 @@ public static bool VerifyDurability3(int durabilityA, int durabilityB, int durab
 
     public static bool VerifyDurability3(Simulator s, int durabilityA, int durabilityB) =>
         VerifyDurability3(durabilityA, durabilityB, s.Durability, s.ActiveEffects);
-
-    public static bool VerifyDurability3(SimulationState s, int durabilityA, int durabilityB) =>
-        VerifyDurability3(durabilityA, durabilityB, s.Durability, s.ActiveEffects);
 }
diff --git a/Simulator/SimulationState.cs b/Simulator/SimulationState.cs
index e743ade..8147cdb 100644
--- a/Simulator/SimulationState.cs
+++ b/Simulator/SimulationState.cs
@@ -18,7 +18,7 @@ public record struct SimulationState
     public ActionStates ActionStates;
 
     // https://github.com/ffxiv-teamcraft/simulator/blob/0682dfa76043ff4ccb38832c184d046ceaff0733/src/model/tables.ts#L2
-    private static readonly int[] HQPercentTable = {
+    private static ReadOnlySpan<int> HQPercentTable => new[] {
         1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8,
         9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 17, 17,
         17, 18, 18, 18, 19, 19, 20, 20, 21, 22, 23, 24, 26, 28, 31, 34, 38, 42, 47, 52, 58, 64, 68, 71,
diff --git a/Simulator/Simulator.cs b/Simulator/Simulator.cs
index 492b4db..03dbb12 100644
--- a/Simulator/Simulator.cs
+++ b/Simulator/Simulator.cs
@@ -35,17 +35,17 @@ public virtual CompletionState CompletionState {
 
     public IEnumerable<ActionType> AvailableActions => ActionUtils.AvailableActions(this);
 
-    public Simulator(SimulationState state)
+    public Simulator(in SimulationState state)
     {
         State = state;
     }
 
-    public void SetState(SimulationState state)
+    public void SetState(in SimulationState state)
     {
         State = state;
     }
 
-    public (ActionResponse Response, SimulationState NewState) Execute(SimulationState state, ActionType action)
+    public (ActionResponse Response, SimulationState NewState) Execute(in SimulationState state, ActionType action)
     {
         State = state;
         return (Execute(action), State);
@@ -75,7 +75,7 @@ private ActionResponse Execute(ActionType action)
         return ActionResponse.UsedAction;
     }
 
-    public (ActionResponse Response, SimulationState NewState, int FailedActionIdx) ExecuteMultiple(SimulationState state, IEnumerable<ActionType> actions)
+    public (ActionResponse Response, SimulationState NewState, int FailedActionIdx) ExecuteMultiple(in SimulationState state, IEnumerable<ActionType> actions)
     {
         State = state;
         var i = 0;
diff --git a/Simulator/SimulatorNoRandom.cs b/Simulator/SimulatorNoRandom.cs
index 1f4c827..e6c4738 100644
--- a/Simulator/SimulatorNoRandom.cs
+++ b/Simulator/SimulatorNoRandom.cs
@@ -2,7 +2,7 @@ namespace Craftimizer.Simulator;
 
 public class SimulatorNoRandom : Simulator
 {
-    public SimulatorNoRandom(SimulationState state) : base(state)
+    public SimulatorNoRandom(in SimulationState state) : base(state)
     {
     }
 
diff --git a/Solver/ActionSet.cs b/Solver/ActionSet.cs
index 24b135d..b7cc97d 100644
--- a/Solver/ActionSet.cs
+++ b/Solver/ActionSet.cs
@@ -9,7 +9,7 @@ public struct ActionSet
 {
     private uint bits;
 
-    public static readonly ActionType[] AcceptedActions = new[]
+    internal static ReadOnlySpan<ActionType> AcceptedActions => new[]
     {
         ActionType.StandardTouchCombo,
         ActionType.AdvancedTouchCombo,
diff --git a/Solver/Craftimizer.Solver.csproj b/Solver/Craftimizer.Solver.csproj
index bf16279..eaea55b 100644
--- a/Solver/Craftimizer.Solver.csproj
+++ b/Solver/Craftimizer.Solver.csproj
@@ -20,6 +20,12 @@
     <ProjectReference Include="..\Simulator\Craftimizer.Simulator.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
+      <_Parameter1>Craftimizer.Test</_Parameter1>
+    </AssemblyAttribute>
+  </ItemGroup>
+
   <PropertyGroup Condition="'$(IS_BENCH)'=='1'">
     <DefineConstants>$(DefineConstants);IS_DETERMINISTIC</DefineConstants>
   </PropertyGroup>
diff --git a/Solver/MCTS.cs b/Solver/MCTS.cs
index 8e40a6b..76251db 100644
--- a/Solver/MCTS.cs
+++ b/Solver/MCTS.cs
@@ -17,7 +17,7 @@ public sealed class MCTS
 
     public float MaxScore => rootScores.MaxScore;
 
-    public MCTS(MCTSConfig config, SimulationState state)
+    public MCTS(in MCTSConfig config, in SimulationState state)
     {
         this.config = config;
         var sim = new Simulator(state, config.MaxStepCount);
@@ -30,7 +30,7 @@ public MCTS(MCTSConfig config, SimulationState state)
         rootScores = new();
     }
 
-    private static SimulationNode Execute(Simulator simulator, SimulationState state, ActionType action, bool strict)
+    private static SimulationNode Execute(Simulator simulator, in SimulationState state, ActionType action, bool strict)
     {
         (_, var newState) = simulator.Execute(state, action);
         return new(
@@ -61,7 +61,7 @@ private static Node ExecuteActions(Simulator simulator, Node startNode, ReadOnly
 
     [Pure]
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static (int arrayIdx, int subIdx) ChildMaxScore(ref NodeScoresBuffer scores)
+    private static (int arrayIdx, int subIdx) ChildMaxScore(in NodeScoresBuffer scores)
     {
         var length = scores.Count;
         var vecLength = Vector<float>.Count;
@@ -111,7 +111,7 @@ private static (int arrayIdx, int subIdx) EvalBestChild(
         float explorationConstant,
         float maxScoreWeightingConstant,
         int parentVisits,
-        ref NodeScoresBuffer scores)
+        in NodeScoresBuffer scores)
     {
         var length = scores.Count;
         var vecLength = Vector<float>.Count;
@@ -168,7 +168,7 @@ private Node Select()
                 return node;
 
             // select the node with the highest score
-            var at = EvalBestChild(explorationConstant, maxScoreWeightingConstant, nodeVisits, ref node.ChildScores);
+            var at = EvalBestChild(explorationConstant, maxScoreWeightingConstant, nodeVisits, in node.ChildScores);
             nodeVisits = node.ChildScores.GetVisits(at);
             node = node.ChildAt(at)!;
         }
@@ -320,7 +320,7 @@ public SolverSolution Solution()
 
         while (node.Children.Count != 0)
         {
-            node = node.ChildAt(ChildMaxScore(ref node.ChildScores))!;
+            node = node.ChildAt(ChildMaxScore(in node.ChildScores))!;
 
             if (node.State.Action != null)
                 actions.Add(node.State.Action.Value);
diff --git a/Solver/MCTSConfig.cs b/Solver/MCTSConfig.cs
index a0e554d..1bf4e3d 100644
--- a/Solver/MCTSConfig.cs
+++ b/Solver/MCTSConfig.cs
@@ -1,4 +1,4 @@
-using System.Runtime.InteropServices;
+using System.Runtime.InteropServices;
 
 namespace Craftimizer.Solver;
 
@@ -21,7 +21,7 @@ public readonly record struct MCTSConfig
     public float ScoreCP { get; init; }
     public float ScoreSteps { get; init; }
 
-    public MCTSConfig(SolverConfig config)
+    public MCTSConfig(in SolverConfig config)
     {
         MaxStepCount = config.MaxStepCount;
         MaxRolloutStepCount = config.MaxRolloutStepCount;
diff --git a/Solver/NodeScoresBuffer.cs b/Solver/NodeScoresBuffer.cs
index fecfb40..5d45e59 100644
--- a/Solver/NodeScoresBuffer.cs
+++ b/Solver/NodeScoresBuffer.cs
@@ -7,11 +7,11 @@ namespace Craftimizer.Solver;
 // Adapted from https://github.com/dtao/ConcurrentList/blob/4fcf1c76e93021a41af5abb2d61a63caeba2adad/ConcurrentList/ConcurrentList.cs
 public struct NodeScoresBuffer
 {
-    public sealed class ScoresBatch
+    public readonly struct ScoresBatch
     {
-        public Memory<float> ScoreSum;
-        public Memory<float> MaxScore;
-        public Memory<int> Visits;
+        public readonly Memory<float> ScoreSum;
+        public readonly Memory<float> MaxScore;
+        public readonly Memory<int> Visits;
 
         public ScoresBatch()
         {
@@ -40,9 +40,10 @@ public void Add()
 
         var idx = Count++;
 
-        var (arrayIdx, _) = GetArrayIndex(idx);
+        var (arrayIdx, subIdx) = GetArrayIndex(idx);
 
-        Data[arrayIdx] ??= new();
+        if (subIdx == 0)
+            Data[arrayIdx] = new();
     }
 
     public readonly void Visit((int arrayIdx, int subIdx) at, float score)
diff --git a/Solver/SimulationNode.cs b/Solver/SimulationNode.cs
index a0c722b..a2b8f34 100644
--- a/Solver/SimulationNode.cs
+++ b/Solver/SimulationNode.cs
@@ -19,7 +19,7 @@ public struct SimulationNode
 
     public readonly bool IsComplete => CompletionState != CompletionState.Incomplete;
 
-    public SimulationNode(SimulationState state, ActionType? action, CompletionState completionState, ActionSet actions)
+    public SimulationNode(in SimulationState state, ActionType? action, CompletionState completionState, ActionSet actions)
     {
         State = state;
         Action = action;
@@ -32,10 +32,10 @@ public static CompletionState GetCompletionState(CompletionState simCompletionSt
         CompletionState.NoMoreActions :
         simCompletionState;
 
-    public readonly float? CalculateScore(MCTSConfig config) =>
+    public readonly float? CalculateScore(in MCTSConfig config) =>
         CalculateScoreForState(State, SimulationCompletionState, config);
 
-    public static float? CalculateScoreForState(SimulationState state, CompletionState completionState, MCTSConfig config)
+    public static float? CalculateScoreForState(in SimulationState state, CompletionState completionState, MCTSConfig config)
     {
         if (completionState != CompletionState.ProgressComplete)
             return null;
diff --git a/Solver/Simulator.cs b/Solver/Simulator.cs
index 8edf3e4..a3a29fa 100644
--- a/Solver/Simulator.cs
+++ b/Solver/Simulator.cs
@@ -20,7 +20,7 @@ public override CompletionState CompletionState
         }
     }
 
-    public Simulator(SimulationState state, int maxStepCount) : base(state)
+    public Simulator(in SimulationState state, int maxStepCount) : base(state)
     {
         this.maxStepCount = maxStepCount;
     }
diff --git a/Solver/Solver.cs b/Solver/Solver.cs
index ca6343e..7c9efcf 100644
--- a/Solver/Solver.cs
+++ b/Solver/Solver.cs
@@ -35,7 +35,7 @@ public sealed class Solver : IDisposable
     // Always called when a new step is generated.
     public event NewActionDelegate? OnNewAction;
 
-    public Solver(SolverConfig config, SimulationState state)
+    public Solver(in SolverConfig config, in SimulationState state)
     {
         Config = config;
         State = state;
diff --git a/Solver/SolverConfig.cs b/Solver/SolverConfig.cs
index d261949..65274a9 100644
--- a/Solver/SolverConfig.cs
+++ b/Solver/SolverConfig.cs
@@ -1,5 +1,3 @@
-using Craftimizer.Simulator.Actions;
-using Craftimizer.Simulator;
 using System.Runtime.InteropServices;
 
 namespace Craftimizer.Solver;
@@ -71,4 +69,4 @@ public SolverConfig()
         FurcatedActionCount = Environment.ProcessorCount / 2,
         Algorithm = SolverAlgorithm.StepwiseForked
     };
-}
\ No newline at end of file
+}
diff --git a/Solver/SolverSolution.cs b/Solver/SolverSolution.cs
index f512479..ce38fce 100644
--- a/Solver/SolverSolution.cs
+++ b/Solver/SolverSolution.cs
@@ -9,7 +9,7 @@ public readonly record struct SolverSolution {
     public readonly IEnumerable<ActionType> ActionEnumerable { init => actions = SanitizeCombos(value).ToList(); }
     public readonly SimulationState State { get; init; }
 
-    public SolverSolution(IEnumerable<ActionType> actions, SimulationState state)
+    public SolverSolution(IEnumerable<ActionType> actions, in SimulationState state)
     {
         ActionEnumerable = actions;
         State = state;
diff --git a/Test/Solver/ActionSet.cs b/Test/Solver/ActionSet.cs
index 0f4c9df..fd8c8a1 100644
--- a/Test/Solver/ActionSet.cs
+++ b/Test/Solver/ActionSet.cs
@@ -1,5 +1,3 @@
-using Craftimizer.Simulator.Actions;
-
 namespace Craftimizer.Test.Solver;
 
 [TestClass]
diff --git a/Test/Usings.cs b/Test/Usings.cs
index da624f8..c58173e 100644
--- a/Test/Usings.cs
+++ b/Test/Usings.cs
@@ -1,3 +1,4 @@
 global using Microsoft.VisualStudio.TestTools.UnitTesting;
 global using Craftimizer.Solver;
 global using Craftimizer.Simulator;
+global using Craftimizer.Simulator.Actions;