It’s a plugin for Decky loader that allows you to control the Steam Deck’s fan
Interesting how they discussed hardware mods but not software mods (for the OS, not for games). I’m probably biased, but I’d think those would be more popular than hardware mods since they’re much more accessible to the average user.
They’re mostly breaking the GUI of game mode, which causes it to restart the game mode GUI. The underlying OS isn’t really affected – you should be able to SSH into an affected system or force boot into desktop mode.