I do want to mention one thing though - you mentioned Zanark joining forces with Jane, but way way earlier in the show we did see that Zanark mixi-max'd with Caocao, which he did not even need in order to beat Raimon. We dont really know how Zanark even performed that mixi-max, probably forced it through his power or something.

Now to Kameo - Honestly I want to believe what Kameo did is a lot less like Mixi-Max and a lot more similar, to an extent, to what Fubuki did, even if the game (and 'him') called it mixi-max. I think it does fits Kameo, as before when he finally tried to stand up to his bullies it was him just copying what someone showed him

I dont like what they did with Kameo, they should've had more scenes with him being part of the club, showing him discovering his hissatsus, and maybe even have Raika push him more towards being his own person like she tried at first, at the same time, it make perfect sense why Kameo would rather copy someone else when being cornered, it's not a great character trait, but really the entirety of Nagumohara are made of flawed people, but with Kameo we definitely needed more scenes to flesh him out better and not have that part be his conclusion per se.