I realise this might be a little silly and not really worth talking about for most people, but I really dislike the choice made with having trust party members level back down to 71 after the main story and requiring you to manually level them up through repeated dungeon runs.
On paper it doesn't sound like that bad of an idea, you can level up your trusts alongside one or two alternate jobs, but sadly the experience requirements for them are straight up ridiculous - at level 71, each trust member requires 6 runs of the level appropriate dungeon in order to level up, that's at least 12 runs of the same dungeon before you can move on to the next one... and that's before you factor in the part where only the 3 out of 6 trusts you bring with you will actually gain experience, doubling that number to at least 24 if you want to level all of them.
Needless to say doing over 24 runs for each of the five story leveling dungeons would drive anyone mad, especially when they very rarely take less than 30 minutes to complete due to the trusts' reduced damage output.
The experience gain is so bad you'll end up vastly overleveling them on an alternate job even if you do nothing but trust runs on it...
This seems like far too much trouble for too little reward, it should either be made way more lenient or just be removed altogether.