The Meta Quest 2/3 finally fixed that a few months ago [1], where you "tilt" the horizon of the entire OS [2]. So it doesn't matter if an app doesn't support it -- you can lie on your bed and watch a screen directly above you even if it was only designed for horizontal use. It's a game-changer if you have back/neck problems.

Does the AVP not have something equivalent? To be honest, I was surprised it took Meta so long to get around to implementing it.

[1] https://www.engadget.com/you-can-now-lie-down-while-using-a-...

[2] https://www.meta.com/en-gb/help/quest/articles/headsets-and-...