I'm not certain that everything is working as intended, but, MP regen works outside of combat, and this effectively invalidates a huge swath of strategies that previously seemed viable.
Since MP regen exists as a bonus on equipment, and you can change equipment between fights while in the dungeon, after every fight you can equip said MP regen gear, walk around for 30 seconds to recover 100% of your MP, re-equip your previous gear, and then move on to the next fight with full resources. Presumably, HP regen works the same, or you can also use a class with any healing skill to refill HP.
Having a free full restore after every fight makes classes that excel at long-term resource management useless, and heavily incentivizes high-MP burst damage classes like Archmage, to the exclusion of any other form of damage dealing.
And on top of all the strategic implications, its also pretty annoying to walk from corner to corner of the room for 30 seconds after every fight, while its also clearly suboptimal not to.
Granted, I'm not that deep into the game, despite my, apparently, 16 hours of playtime, having only done remembrance missions for a handful of characters, and mostly ignoring the main quest in favor of trying out a wide variety of classes for at least a few levels. So it is possible that the game becomes balanced around starting with full resources every fight, --and if this is the case, hopefully also unlocks an automatic heal, instead of having to swap equipment, walk around for 30 seconds after every fight, and then try to remember what you had equipped before to swap back,-- it would likely still have a similar impact on teambuilding strategy, where most of the available options are simply overshadowed by spending all your MP on as much damage as possible as quickly as possible.
I see this as a critical flaw in the otherwise remarkably intricate design-object of this game, and I hope that this isn't how its supposed to work, and that it gets patched soon, so that I can properly engage with all of that wonderful intricacy.