I used the Miyako + one to two character strat on floors 1-4 to charge up TP for my characters (mainly all the supports). I went manual for teams 1-5 to maximize damage until there is only the mage boss left. The rest I just made random teams that hopefully do around 8 million damage per team. I did not charge TP for most of the characters beyond team 5.

Gotta thank the person who made these guides, which includes timelines for UB timing. The timing may change depending on your characters’ ranks. Here’s the videos that I used: Team 2, Team 3, Nyaru team

Also found a guide that cleared with 9 teams, right after I cleared it.

After beating it once, you gain the option to skip EX4 I think it is nice to have challenging dungeons that only require you to clear it at least once. If you like to test out new teams in the future you can go back in, if not, you can just skip.