@Ralf, I actually was able to figure out a way to do this. I tried it initially but it didn’t work, think I forgot to hit apply.
1) On Desktop, open VorpX config App, go to, in-game key bindings, changed “VR Hotkey Menu” from ‘Shift+Middle_mouse’ to ‘p’.
2) In the game, open VorpX Menu
3) Go to Oculus Hand Controller Menu. At bottom, click into Change Button Mappings.
4) here I mapped the Oculus ‘Y’ button to keyboard ‘p’.
Then it worked at least in Immersive Screen Mode.