Since there's a dev team contact here (probably, can't say for real with them being Guest and such ) I may as well give some of my feedback.

Rebellion event is GREAT... once you figure out that main reward is getting the one of paywall premium 5* characters for free and stop shooting for the top place . It's biggest draw that players can run it basically for free, by just farming normal maps, strengthening their teams and so on. Equally (for me) good point is that it has visible and steady progress, being point accumulation and all. It feels good to see that every drop of resources you pour into it pushes you forward to the goal! And the set-point huge payoff map that unlocks with stamina spent is the greatest thing ever!

Adv Dojo, on the other hand, feels terrible in comparison. Not only it forces one to forgo all other activities and cut into other event's progress, it is also of the worst kind: that throws you at the (nonexistent) mercy of Random Number Goddess by forcing you to farm drops at the laughable chances. Or asks for a very specific compositions of gacha 5* (and we all know just how much they are (in)accessible for non-whales), fully evolved / godified at that, for better rates, all while still facing a very grim possibility of game laughing at your face by spending several hundreds of stamina points for no progress at all with dry runs.

Both feel a bit too grindy. Halving the requirements and duration might make them feel more dynamic, in my opinion.