[nix0n]

There are QOL mods[0] available for that version to get the camera (and controller in general, and other stuff) working better.

Can't speak to the Deck HW or Steam OS specifically, but the SilentPatch and GInput mods have been working great for me on Proton under Linux Mint.

[0]https://cookieplmonster.github.io/mods/gta-vc/