Note: This issue is my fault for not backing things up manually. (would be nice if the game supported cloud backups, but it doesn't look like that will happen) This is more of a warning to others who might be thinking of temporarily uninstalling the game.

I am also playing on a Steam Deck through Plasma GE 9-05 (with reshade 6.1.1 installed via STL).

I uninstalled the game a couple days ago to temporarily make space for Besiege. I didn't clear my proton files as I wanted to come back after checking out the new update. When I reinstalled Plasma, however, all my worlds and devices were gone. This includes the devices
I "uploaded" to the workshop. My subscriptions and reshade files were fine, Thank Goodness. 😒

Love learning lessons the hard way. Moral of the story: You can never have enough redundancy backups. I saved my worlds often, saved as a new world daily and before performing risky things. I saved devices I cared about and saved as a new device just in case. In the end, I still lost it all because I didn't open the file explorer and create a backup of all my user data before uninstalling.