My initial interpretations of Hexdrinker and Barkhide Troll were incorrect. We should definitely test them out. We have to either cut lands or Steel Leaf Champion or a mixture of both for them though.
Also Veil of Summer is an auto include as a 2-3 of in the sideboard- maybe 4 of. The only reason not to is your specific meta doesn't have blue or black.
Even if the meta is blue or black, i prefer to sideboard threats rather than replacing veils with a deck giving hexproof to creatures or the Barkhide Troll having a built-in hexproof. I've been playing with control and BGx decks and I'm not obliged to put veil. Yes it can replace itself, but seeing another variety of Vines of Vastwood is a big no.
The list just went 5-0 in a modern competitive league... looks like the Barkhide Troll is a good addition to the deck.
Even if the meta is blue or black, i prefer to sideboard threats rather than replacing veils with a deck giving hexproof to creatures or the Barkhide Troll having a built-in hexproof. I've been playing with control and BGx decks and I'm not obliged to put veil. Yes it can replace itself, but seeing another variety of Vines of Vastwood is a big no.