Yeah, upon further investigation, I think that you're right.

Annoying. It'd be much better if it'd just write a tag and players would respond to that tag. Even better, it uses APEv2 tags to store its analysis and undo information instead of the probably already existant ID3v2 tag, just to add to the bloat a little bit more.

Still, it definitely modifies the Xing/Info tag, too. Maybe that's just metametadata.