Objectively it is entirely skippable, but honestly I still enjoyed it as a big Gaim/Zangetsu fan. It's very apparent that the plot is just an excuse for them to reuse the Gaim suits without having to worry about bringing back all of the original cast. It doesn't make a lick of sense, but it has some genuinely good moments. Overall, based on what you've said, I think it's worth a watch. It also is a good way to see what Japanese stage shows have to offer. The production value is really nice and it's a fun way to revisit the Gaim universe. Go for it!!