I didn't even noticed there was new floors. I'll try this right now and I hope I wont need to many evolved equipments.
Actually, the event equipements since the previons christmas event can be evolved too. Not only the centies ones. It's a bit too expensive but more affordable than the personal equipments. It's a good solution for thoses hard floors.
Edit:
I'm pretty sure there is a trick with lvl180 boss healing. It's too inconsistent and it would be totally unfair if it was random. I think it could be related to the girls' nation. I tried a team full of Winter Rose and it never healed (over 2 turns...). With a team full of Blossom Hill, the boss got a 100% healing turn 1.
I guess devs want to force us to use the equipement bonus here.
Edit2:
Lvl 180 done with good old Cattleya magic. I still don't understand how the heal works but the boss didn't healed at all. It seems it's not related to nation after all. Maybe related to girls skill activation. I don't know.
If it could help, I used that team: