Okay good news! I was able to build a Linux version of MageQuit and a friend of mine was able to start it up on his Steam Deck, so you should be good to give it a shot too!
For now, It'll be under the beta branch, so in your Steam library, you can right-click (or whatever the equivalent is on a Steam Deck touch screen) MageQuit, select the Betas tab, type in "magequitisfun" as the code, and then switch to the Beta branch.
Also, under the Compatibility tab, you may need to check the "Force the use of a specific Steam Play compatibility tool" checkbox and then select "Steam Linux Runtime" from the dropdown.
You'll know if you have the right version if the version number in-game says "v2.4.5a (linux)"
Hopefully that'll actually start up for you!