Finished Terra's reports yesterday, so all optional bosses beat. Went easier than I thought, learnt a bunch of neat tricks I never knew about in the original game too.
Can beat Vanitas sentiment by going behind a rock and just keep using strike raids.
And a good level grind trick, go to the reactor in radiant garden, disable exp walker/treasure magnet if you have them, get to under 25% HP to activate EXP chance ability, then go to the middle to spawn the enemies, dash back, mega flare, use victory pose to get more EXP out of it and repeat.
Think it took about 4/5 loops of that to level up for Terra at least and beat all the bosses at level 60, (then grinded to 70 for No Heart, wasn't dealing so much damage to him and was getting wrecked ha ha).
Just remembered that in KH3 we're getting a Big Hero 6 world that isn't going to be a retelling of the movie. I hope that all future worlds follow this and don't retell the movies.
I would like a mix of both for this really but Yeah would like more of this at least.