Ah, tell me about it, adding new clothes for multiple shapes can be a bit….nightmarish. You have no idea how long it took me to adapt everything on the facesets for every different shape/skin. But I believe it was worthwhile!
For patterns the only thing that is strict about naming are the skins - I noticed that I completely forgot to add that on the documentation, thanks again for the headsup - so they should follow the naming convention:
shape##_skin##.png (charsets directory)
skin##.png (facesets directory)
This way the engine knows what shape refers to what skin and how to build the proper path for the facesets. Since we are dealing with just 2 shapes for now, you will have both shape00_skin07.png as well as shape01_skin07.png. Then your facesets directory will have under both shape00 and shape01 a folder named skin07 with skin07.png inside of it following all the clothes that match this combination of shape and skin.
Asides from that all that is required is that the files - let’s say, breastplate.png - should have the same name across all folders, so the tool know what .png to point at.
EDIT: Oh yeah, if anything goes wrong, the tiny terminal/console on the tool will tell you which file is missing.