I see theres an android version of gui emacs as of version 30.1, but would I be able to run it within the quest 3? Which limitations would I run into? Could I run pdf tools and the latex preview feature in auctex? Would i be able to download stuff from melpa?
LOL, just no. That’s certainly no laptop replacement for more reason than one.
You can’t simply run 2D apps on Quest (regardless of which one), they have to be built specially for Quest to actually display properly in the 3D mode.
Normal “2D” apps will not run properly, you will get all sorts of glitches and issues, with the OS switching between the 2D and 3D mode, with the 2D mode being extremely jarring.
With the multitasking support in Quest 2/3 you could have it displayed as a window - but not really full screen and your text readability (which is suck in Quest already) would suffer even more unless you blow up the text size.
Very limited battery life and the general ergonomics of the device are also very good reasons why this is not a laptop replacement of any kind.
If you want Quest, buy it for playing games. That is what it has been designed to do.
If you want a laptop, use a laptop. If you don’t want to lug a laptop around while traveling (even though Quest 3 is not really any smaller with all the accessories you need to carry about!), get a Surface tablet or even an Android tablet and a keyboard. Even with all their limitations it is a much better portable solution than trying to use a Quest for this.
How abt a steam deck? What is the consensus on using it in desktop mode?
I don’t know “what is the consensus” because I don’t have one - but why are you insisting on carrying around a gaming console to use it as a (crappy) laptop? What are you going to gain here?
You will still need a keyboard, mouse, possibly a second battery, charger, something to put all that stuff in … At that point you can as well buy a 13" laptop and be done with it.