Sounds like you're not using transpose enough TBH. At that level it really is your best friend. Funny though it goes from key ability 1-50 then you kinda fall out with it 50-60 but you make up and become best friends forever 60-70 and by 70 it's your EB partner.
Using this you really should never lose timer. I can run an entire dungeon and never run out unless forced to through cutscenes or non-attack sections but even in Hells Lid when the final boss switches to shield, transpose right before it and you have plenty time to get back on the attack and not lose AF, UI or Enochan. Similar to be applied In other dungeons.