- Edited
Should have updated. After fixing
- the .json export so that it also does this for Linux
- the capitalization errors that I had. I just had two typos where I had given a capital D to the "/data" in my URL, and found out this is not a problem for Windows as it's apparently not case-sensitive even though you can use capitals in folder names, but is a problem for Linux that then goes looking for the wrong file.
it now works on Linux as well! Seeing that it really said "file not found" made me think again whether the json files were actually included and made me click around more in that export window, finding out those settings are applied per export template. So the fix was also in the lines of what I originally expected, as I was always told Godot can still read from res, it just can't write to it.
I've been since working on a presumably wholly unrelated performance issue. Steam Deck is not handling the lights as well as my desktop is (which makes sense, my desktop has a beefy GPU)