Do not cut powders. You need every rebuy on mulligans you can get because bazaar and sideboard cards are that important in the matchup. I've never cut Bridges/narcs/stinkweed/troll/bazaar/powder. That's the bare minimum the deck needs to function properly
Noard out misstep. Board out therapies, Board out maybe a few lands as most lists need them postboard against shops but you'll only need 1 rainbow to cast wispmare/CoV/Nature's claim. Board out ichorids.
Postboard becomes a race to Elesh norn most games.
@gkraigher Castable creatures aren't a thing. Therapy is just a worse wispmare with mana available, as you get tokens and remove theirs and hits leyline. It's not so bad that I cut them first (removing bridges is a big deal for sure) but usually I have enough to bring in that they get cut anyway.