Of course you can

export SUDO_PROMPT="tell me your safeword first: "

It’s probably because you need to go to Steam settings and enable Proton for all games. I don’t understand why this is still not turned on by default…

GIMP supports JPEG XL natively in 3.0 development versions. If I remember correctly GIMP 2.10 was released before JPEG-XL was ready, so I think that’s the reason. They could have added support in smaller update though, which was the case with AVIF.