There is no disadvantage to having some extra cards to swap, but having a sideboard is not necessary to play, just a suggestion
Im a believer that someone breaks this in Modern and/or Legacy, likely in some kind of aggro or burn build
Rainbow Dredge (Todays Version) Creatures Spells Lands How the deck works I like to refer to this new version of the deck as Rainbow Dredge, as it adopts the rainbow lands in the form of City of Brass, Gemstone Mine and Mana Confluence Dredge is primarily a combo deck that is built around using the dredge mechanic to create an overwhelming amount of free card advantage
I think it'll suffer from the same speed issue as Threshold, though, as it won't be castable for 1-2 CMC until around turn 5-6
You only need one Yawgmoths Will to win the game, so its not like you really want to draw two
2020-01-24 If an activated ability or triggered ability has an effect that depends on your devotion to a color, you count the number of mana symbols of that color among the mana costs of permanents you control as the ability resolves