Yep it is very hard.
Only for sure way i have found to test that i can trust is using two PC’s.
One with an HMD, the other without (i only have 1 after all)
At the end of the day, you will need two pc’s and two headsets.
Anything game logic related can be tested using pawns without vr.
My process is to do a build, and copy it to the other PC and start it on both.
This way i can test all replication, and steam sessions.
Tedious, but once you have the base down, you know what you changed and what effects what (famous last words) so should not have too many problems.
I also run stat startfile every time and look at the network stats to make sure i don’t blow anything out.