I understand the default URP SkyBox and post processing stack are expensive. Have you tried disabling them and see if performance improves?
From what I hear, the new XR processor should more than compensate for the increased resolution, so I doubt that's your issue. I'm not going to be much more help - I'm pretty much a novice with Unity/Quest. But first thing I do when starting a URP app is replace the SkyBox and disable to post processing, so I thought I'd suggest it. I'd offer to test your project in my environment, but I only have the Quest, not the Quest 2 (yet!)