Beauty and the Beast is way worse in terms of being overcompressed. As far as anime goes, I do have titles with worse compression and ringing. But I'm not going to mention names as they are generally from very small companies that are making an effort and I'm not going to bash them online.
Alternate angles, not seamless branching, are typically used for the credits on these discs. Of course, the alternate angle multiplexed stream is only in use during the credits.
I really like storyboards. Having them all, synched to the soundtrack, is the best extra for an animated film I can imagine. I've never understood why many people look down on storyboards as an extra.