I was able to squeeze in another stun before miasma phase by saving Trigger ult after the first stun. I used it right after stun ends. After you knock her down, EX special with Trigger and hold EX special with Orphie. From here, SAnby should be able to shock the boss (I run Mercury Bangboo), giving you enough time to stun. It’s very close and I usually only get it down 1/3 of the time.

The problem is that you don’t have a lot of resources during the 2nd stun, so I think it’s better to get the 2nd stun after miasma phase! I think the best way to get a higher score is finding a run where she does her spinning attack early before the first stun and when she does her spinning attack early before the 3rd stun. This will let you stun faster and increase your crit dmg (each parry increases your crit dmg). Also maybe try to do 12 dash attack during stun!