I run a g2 with a 2070super and I get a steady 45ps, so your 3080 should be able to get a decent 60-70 with the right settings.
You might want to look at your driver version first for your video card. I still have 457.30 going as it's given me the best in terms of consistent VR performance. The later drivers seem to be geared more towards the 30 series cards so you may get better performance from the latest drivers there.
I would look at your steam super sammpling to start with and make sure it's at 100% (i also have a quest2 and have to play around with the SS settings all the time depending on the headset) I would look at a few settings in Content manager ( if you have it, if you don't get it the free version is good the paid one is better) and look first at the smoke settings and if it's not on low drop it back to that, then move to the shadows and put that to 256x256 to start with, then do the same with the reflectons and set to either 3 faces per frame or static ( you can bump them up higher later once you get your desried frame rate, or an acceptable one.) turn off the anistropic fitering in the game and use the one in Nvidia control panel, it does a better job to frank. Set your mirrors resolution to 256x1024 and high quality. In custom shader settings turn off the extraFX settings, they don't do anything in VR (as yet)
If you're running SOL2 with this as well as CSP you may need to pull back a few settings ther too, specifically the cloud distance multiplyer, quality and frames used ( ignerally have them at 80% 60% and 5frames)
If you are running any PostProccessing I'd run natural mod as it's really well optimised for use in VR.
I'd also recommend Andrew_Wot's guide too but what I've put here should help give you a baseline to tweak. Hope it helps.