Maximum summoning is officially in Go Rush, as of the last few episodes, and it looks as if the show might be gearing up for a duel between it and Fusion summoning, or at least the Rush Duel equivalent of the latter.
A thought that’s recently occurred to me is, given how the cast of Sevens and Go Rush have so far reacted to Maximum summoning, equip and fusion spells, monster reborn and the like, how they would react to Quick play or continuous spells.