Player framerate performance degrades when Spatial and Plane Meshes are updated

How to reproduce:
1. Open the attached “IN-98419.zip” Project
2. Build and Run on a VisionOS Device
3. Observe the FPS in the custom UI Window shown in the Player
4. Spawn multiple GameObjects in the Player with the Pinch Gesture
5. Move the Headset around and observe the FPS in the custom UI Window in the Player

Expected result: Stable framerate performance around ~90fps
Actual result: Erratic framerate, drops to ~70fps very rarely goes lower

Reproducible with: 2.2.4 (6000.0.49f1, 6000.1.4f1)
Couldn’t test with:
1.3.12 (2022.3.62f1) - Compilation errors related to unsupported methods after downgrading
2.2.4 (6000.2.0b2) - IL2CPP Compilation error during Build Time

Testing environment: macOS 15.3.2 (M3)

Reproducible on: Apple Vision Pro 2.5

Notes:

• User has noted that the issue happens due to “Spatial Meshes” or “AR Planes” being updated every frame
• The Project is based on the Unity Polyspatial Sample, specifically Mixed Reality demo