Most of your sideboard cards don't do much here: Tormod's Crypt does nothing to stop Phyrexian Dreadnought or their counterspell suite, and Compost only triggers off black cards going to an opponent's graveyard, which never happens here. Phyrexian Dreadnought is an Artifact Creature, though, so Disenchant and Naturalize are legal answers to it and are worth bringing in as extra removal alongside Swords to Plowshares, which is your key removal spell and should stay in at full count. This matchup otherwise comes down to your maindeck aggression and cheap threats racing their turn-one Dreadnought, so keep the rest of your build as-is and focus on curving out fast.