Hm, I looked into that and what addressables does is forces you to duplicate the entire Resources directory to a Resources_moved folder. I'm guessing at that point the textures are no longer considered resources. Which means PaperDoll wouldn't be able to access them any longer. I'm guessing what you're recommending is rewriting paperdoll to use addressables instead.
I've set up a fresh project and I'll lean into attempting that. If I get it working I'll send the code your way. Do you have an email I should shoot it over to? Consider any of my changes MIT/X so you can integrate and resell it without restrictions.