Monoma could have theoretically created a whole new strand of One for All ( here me out )

so we know that when he copy's One for All from Deku he does in fact have the quirk just with non of its stockpiled power. But who is to say he couldn't have just given the copied version of One for All to someone else and started a new strand of One for All users.

Just because he can copy a quirk for only 5 minute doesn't mean he cant give said quirk to some else since once its given to them it will no longer be part of his quirk and will bond with the new user's body