i mean you can look at what other melee, outlaw specifically are doing for queen on logs. You can stand on the edge of the circle, do your rotation and press s while dodging the slime waves, which has a predictable pattern as well. If you wanna be fancy you can even max time and grapple to counter her suck. Adds pretty much all spawn in the same place where people stack for roots or drop the mechanic in p3. you can literally hold 1 vanish and crackshot them without much problem
Youre also focusing on that one part. Even if during intermission you stood back with ranged, pistol shotted and focus purely on dodging, its still possible to have a decent performance on that fight. Your not parsing poorly because you stuggle to attack the boss during intermission.
That fight is so choreographed, you pretty much should know exactly where you need to be, for uptime.
Regarding ground clutter and visual bloat. If you feel like youre in danger and you cant see anything. Just press cloak and feint, that should be your panic button.