Nice guide! Concerning the launching without steam vr it works to just use "launch game" from the contextual menu of the virtual desktop icon on the system tray. It opens a window to launch an executable, I click on vam.exe and it's all good. Vam being the only game I use this technic for, the window directly opens on it (last launched) so it is always only 3 clicks away -which might arguably be one click more than with the bat file if you have it on your desktop so... I see how this is not such a useful comment.
But to redeem myself I want to add this ensemble of tricks I discovered today by trying to obtain a smooth ride in No Man Sky VR, someone on reddit linked it and it is for a thorough but quick to do guide:
https://www.youtube.com/watch?v=mc0xk06RRTE&t=151s , it helped me a lot for performance in general, which also increased in VAM ;)
