Vulkan is a Graphics API like OpenGL and DirectX. What this means is that as mentioned apps, games, etc have to be made to take advantage of it. You can't just force it and every app, game, etc will run it. Graphics API's don't work that way.
Formatting data will wipe out all of your user data. Any installed apps, texts, call logs, etc will be wiped out. Flashing MSM Xtended will get rid of TWRP since it flashes a new kernel which is why you flash TWRP after flashing the rom.
So if you want to keep your apps, their data, texts, call...
I was on OOS 10.0.1 as I mentioned, so I followed this:
1. Reboot to recovery
2. Format data
3. Reboot to recovery
4. Flash MSM Xtended
5. Flash TWRP for Q
6. Reboot to recovery
7. Flash ExLite Normal GAPPS
8. Flash Magisk v20.1
9. Reboot to system
And that did it for me
I highly recommend it. I think I've found my new daily custom after thinking I'd have to give up custom roms on my 6T. I don't see any reason the beta shouldn't work though but I understand not wanting to risk it.
If you're using XDA Labs, try viewing it in browser.
I installed it using OOS 10.0.1 Stable and it seems to run perfectly fine. Very stable rom so far and I'm enjoying it a lot. Good job!
I used ExLite Gapps on install instead of OpenGapps.