The upcoming clip from a co-op playthru exhibits that Misery's damage threshold before teleporting (that is, how much damage she takes before going intangible and moving to another location) is higher during coop runs. However, her HP appears to remain the same.

This opens the possibility of opening coop (by using the main pause menu and adding a player 2) to make this battle faster. Player 2 does not need to have a controller attached to be activated, and can be removed using the same menu, so this poses no accesibility issues as no spare controllers are required.

However, this brings up a potential legailty issue: there are no rules about activating player 2 during a single player run. My stance is that 2nd player should be allowed as long as it makes no input. However, I'd like an official stance from the runners before making progress on studying strats involving added coop.

I did some testing with 2-player mode today. I don't have all of the data ready yet (I'll probably post it somewhere when I do), but so far, it's looking like every single boss gains more HP when the second player is activated. I also looked into Misery and found that, although her damage cap per round does indeed increase from ~80 to ~120 when the second player is active, her HP also correspondingly increases from 500 to 750. In both cases, Misery requires around 6 rounds to defeat, so I don't think the 2P strat is going to save any time.

Empirically, I've noticed that 6 rounds is more than enough to defeat 1P Misery (better runners than me have even managed to do it in 5), whereas beating 2P Misery in 6 rounds is actually somewhat difficult (oftentimes she ends the round with like 6 HP to spare, and so I have to go through a 7th round).