Does this still work? I tried to convert a .yy room to a .yaml and I got the error Reading...An error occurred: Invalid char 125 at position 343. This is normal GM room without any hand modification to .yy file
In GameMaker Studio 2.3 (2020-ish) and newer, each resource takes up one line in YYP (or .resource_order), so the original problem that this tool solves no longer exists.
Would have to rewrite most of it to make it work with current versions, and even then I’m not quite sure how the IDE orders resources in the YYP