VR MSAA 4x dropping fps

Unity VR URP: Achieving 72 FPS with MSAA 2x, Dropping to 30-40 FPS with MSAA 4x on Pico 4, Handling 300,000 - 500,000 Triangles and Real-Time Hard Shadows in Scene

What is the question?

How can one improve performance with MSAA 4x, and why is the difference so significant compared to 2x?

With higher resolution and a worse Snapdragon than the Quest 3, realtime hard shadows and MSAA 4x might be too much for the device.

Are you using any post processing as well? If you are, that might have to go.

Is there a way to offload some of the workload from the GPU to the CPU?