Qbert VS holoiso

I'd recommend qbert rather than disabling the read-only filesystem. It survives updates and you can just turn it off if you want to.

But if you do, qbert will make it behave like a normal arch Linux so you can follow the tutorials on the internet.

This was recommended to me: https://github.com/XargonWan/Qbert

Also, I would advise you use Qbert or Junest to install it, instead of making the filesystem writable, because a SteamOS update will wipe all that data

To do that, you will either need to unlock the read-only part or use qbert to get the same effect in a way that can't break stuff.

for pacman on deck you can use qbert, which will let you leave the system read-only and lets you keep your files between updates. You can even put it into .bashrc so it runs automatically on boot.

exclusive to the deck for now, unofficial ports exist, and official support is coming soontm

HoloISO: https://github.com/theVakhovskeIsTaken/holoiso

if you haven't seen it yet, some dedicated members of the community already made a working desktop iso (amd only obviously)

I don't recommend installing SteamOS because it may not have the drivers, I'd recommend HoloISO if you want something more akin to SteamOS, or just use the new Big Picture mode.