I just stumbled upon an inconsistency which is likely to deceive editors: Guess Case behaves in two different ways on collapsed mediums.
Case 1: if a medium is automatically collapsed (e.g. because the release is very large), the global Guess Case button does not affect that medium.
Case 2: if a medium is collapsed by the user, Guess Case is applied even if its effects are not immediately visible to the user on the Tracklist Tab.
I would argue that the first behaviour makes more sense and should be applied in both cases.
I didn't test this with other editing buttons (Reset track numbers, Swap track titles with artist credits, Guess feat. artists from track titles), but I imagine those use the same logic and should be updated accordingly too.