1 year later, and I’ve started to use the ovr metrics tool. It looks like unity terrain is the still the single biggest hit to my game even with extremely low settings. Are there any more recommendations out there to get utp terrain more performance on the oculus quest?
Short of converting terrain to mesh and moving any texture/splat) space vegetation over to a mesh, which is another valid and traditional method.
There hasn’t been any more unity terrain system optimisations since (launched) sadly.
New technologies and ideas about yes, but still very very very experimental, and would be even more so for VR cpu limits
Providing consistent feedback to Jeremyco and the like can help expedite these sorts of development process and honestly I can only ever recommend providing viable feedback whenever possible.
I would look on the side at a mesh based solution, if you have an inexpensive method of that right now great, just set up a test scene so to not lose terrain data, splats veggies etc.
And profile any performance gains.
The potential downside would be you’d be giving up your microsplat workflow this way, and of course it’s a completely different terrain workflow,
but it’s just something you’ll have to test for in you specific development environment to judge whether it gives you those gains you, need.
You are able to turn off terrain draw, shadows ( or not) and keep any space tree or vegetation you may be using on it, and simply replace it with a mesh version of the same terrain too.
This is probably what I would attempt next if I were in your shoes.
Have the same problem in 2023 
.
SImple 130x130 terrain with 3 textures and no vegetations eats -20 fps on Quest 2
Just can’t understand why Unty team can’t figure out some solution
for such popular and important thing like terrain.
Will try MicroSplat or any alternative.
If anyone is interested, tag me and I will reply
Yeah you really just have to use a mesh for a terrain, not the unity terrain. I like to make my terrain with unity terrain tools and then convert to mesh, and I like these shaders
https://assetstore.unity.com/packages/tools/terrain/terrain-to-mesh-195349
You should see a drastic improvement
https://github.com/jinsek/MightyTerrainMesh
Here is a free alternative, works amazing and even supports LODs