The effects of anti-aliasing 4x on GPU utilization

Hi,

We are building a game for Quest 2/3 and we hit some hiccups with anti-aliasing destroying GPU utilization. In Quest 3, without GPU Utilization, our game runs around 50-60% GPU Utilization usually. However, with the 'Use Recommended MSAA' setting on OVRManager, where 4x anti-aliasing is enabled, the GPU utilization jumps to 99% leading to FPS drops.

So we did an experimentation, where we just placed an empty scene with just OVRCamera object, and experimented with diff anti-aliasing options and its effect on the GPU, with these results:

Anti-Aliasing option vs GPU Utilization

4x ~ 50%
2x ~ 33%
None ~ 18%

So my question is, the oculus developer docs are mentioning the cost of 4x MSAA is low and that we should turn it on, but how come its consuming 50% of the GPU in an empty scene? I'm wondering if theirs something fundamentally wrong with how we set up the project, or if this is expected behavior. Maybe I'm totally missing something obvious.  

Thanks!