Compare part lists between Stud.io models?
Since there doesn't seem to be a tool, I've written my own one. In case anyone else want to use it, check it out here: https://github.com/ChrZae/bricklink-xml-diff

Take care tho, it can only really process the XML generated by Stud.io, the XML-format itself has more fields which I didn't care about (also no guarantees it will always work correctly).