Edict effects and most Smother copies are weak here since Phyrexian Dreadnought sacrifices itself anyway unless they have other creatures with enough power, and their other threats are minimal, so cut them for proactive disruption. The extra Duress copies strip a counterspell before you commit a threat, buying a window to land Pernicious Deed or a creature. Tranquil Domain stays in the sideboard because their main deck has no enchantments to hit. Tormod's Crypt can strip Flash of Insight flashback and other graveyard value in grindy games; prioritize Duress and hand disruption over niche artifacts. Keep Pernicious Deed in as your best answer to a resolved Dreadnought or Powder Keg, and keep Cabal Therapy in as hand disruption: it can only hit a card still in their hand, so name a counterspell or a threat like Dreadnought before it is cast, since it cannot touch a permanent that has already resolved.