Going with debuffs against expert Envy isn't all that painful if you can maintain control. Again, not hard when you're soloing, but that goes out the window when there are multiple people.
That said, if there's other people there and you know for a fact that everybody else is auto-ing? Just attack when you know that your attack will turn the demon from raging to stun so you can progress a turn without the demon advancing toward its next overdrive. Mind you, don't necessarily cast debuffs just yet, because you never know when the others trigger a raging overdrive. You're mainly just killing time/contributing some damage until the others auto themselves to death, then you treat the remainder of the fight as a solo battle.
If someone else is playing manual and noticed the above tactic? Ehhhh, I got nothing beyond 'hope you guys hit hard enough for the battle to be short anyway'.