Hello, I'm glad you find my add-on useful daily!
I've added the feature you requested :) I agree, this is pretty useful!
Great addon! I still get a bit confused by the folder behavior with masks and stuff (somehow it works different as I expect after years of working with Substance Painter) but I can't pinpoint on what... but besides that, it's great and I'm sure with more time it will be even greater.
I love this add-on, I use it a lot on my daily workflow when creating avatars and stuff, and I'd love if there was somehow an option to change the suffix it adds with the mirror button? I mostly need the shapekeys to be renamed with Right / Left instead of R / L, and would love if that could be added as an option... Thanks!