We need a Mod to allow 6 players + DM on D:OS 2, do that and this game will distroy Roll20. (And i would be very happy about that)
Bringing up roll20 is pretty off-topic, but even then... I doubt it'd destroy Roll20 even then, because just for one there are tons of games that require more dice than just one to be rolled, or modifiers, or are based around playing vampires or werewolves or aliens or things other than dwarves, elves, lizards, humans, and skeletons.
Not to mention some games go well beyond six players.
