no need to say sorry - those are good questions and the guide needs an update. <3
Generally, if youre using VirtualDesktop with a launch.bat to bypass SteamVR, youre golden. This guide's performance improvements revolve around a cable connection and native VR software like the MetaQuestLink.
For VirtualDesktop, the bad Asynchronous Spacewarp gets replaced with the awesome Synchronous Spacewarp, which is waaaaay better than the Meta counterpart and actually improves smoothness instead of taking it away. Can definately recommend setting the "SSW" to always in the VD streaming settings, unless you have a beastly machine that pulls of stable 120fps on its own.
So if we are using VD without SteamVR the only optimization that makes sense is SSW? no need for vrmodapp?
I have tried SSW, and I'm not sure if it makes a difference, my scenes (not too complex, only 2 persons usually) are running between 20 and 40 fps
Also I think there is a big debate about if it's good or not (I'm wireless btw):