It's the lease that will determine budget apportionment-not the MUD Act. MUD cannot change the lease. As long as the budget apportionment per unit type is fair for all unit types, what you say could and should never arise.
However, your OMC could seek to change the apportionment, but it would be an expensive legal exercise and the change would have to go to a vote of the members. If the majority are adversely affected by the changes, they have the right to block it.