Hello!
I have maybe an impossible suggestion, possibly just a question:
Is it possible in MCreator through coding or some other way to make our mod items fit into the baubles slots? Add the baubles mod as a dependency and work from there?
https://www.curseforge.com/minecraft/mc-mods/baubles
I certainly don't know coding and I'm not sure how hard would it be to do this, but it would be amazzzzzing!