Went back to HDR being derived from camera HDR settings. Maybe not entirely correct, but definitely less error prone.

Assets/Scenes/SampleScene.unity

@@ -319,7 +319,6 @@ MonoBehaviour:
   qualityMode: 2
   performSharpenPass: 1
   sharpness: 0.8
-  enableHDR: 1
   enableFP16: 0
   enableAutoExposure: 1
   preExposure: 1

Assets/Scenes/SampleScenePPV2Post.unity

@@ -322,7 +322,6 @@ MonoBehaviour:
   qualityMode: 3
   performSharpenPass: 1
   sharpness: 0.8
-  enableHDR: 1
   enableFP16: 0
   enableAutoExposure: 1
   preExposure: 1

Assets/Scripts/Fsr2ImageEffect.cs

@@ -44,8 +44,6 @@ namespace FidelityFX
         [Tooltip("Strength of the sharpening effect.")]
         [Range(0, 1)] public float sharpness = 0.8f;
         
-        [Tooltip("Make use of high-dynamic range render texture formats and tonemapping adjustment during upscaling.")]
-        public bool enableHDR = true;
         [Tooltip("Allow the use of half precision compute operations, potentially improving performance if the platform supports it.")]
         public bool enableFP16 = false;
 
@@ -144,7 +142,7 @@ namespace FidelityFX
             
             // Initialize FSR2 context
             Fsr2.InitializationFlags flags = 0;
-            if (enableHDR) flags |= Fsr2.InitializationFlags.EnableHighDynamicRange;
+            if (_renderCamera.allowHDR) flags |= Fsr2.InitializationFlags.EnableHighDynamicRange;
             if (enableFP16) flags |= Fsr2.InitializationFlags.EnableFP16Usage;
             if (enableAutoExposure) flags |= Fsr2.InitializationFlags.EnableAutoExposure;
 
@@ -366,8 +364,14 @@ namespace FidelityFX
             // Shut up the Unity warning about not writing to the destination texture 
             RenderTexture.active = dest;
         }
-        
-        private RenderTextureFormat GetDefaultFormat() => enableHDR ? RenderTextureFormat.DefaultHDR : RenderTextureFormat.Default;
+
+        private RenderTextureFormat GetDefaultFormat()
+        {
+            if (_originalRenderTarget != null)
+                return _originalRenderTarget.format;
+
+            return _renderCamera.allowHDR ? RenderTextureFormat.DefaultHDR : RenderTextureFormat.Default;
+        }
 
         private Vector2Int GetDisplaySize()
         {