There's ideal and there's practical. Ideally it'd be perfectly balanced. I've serviced these rotors and have a hard time picturing a load where the rotor would fail before the mast would. Time and duty cycle play a big role in this, for "temporary" I wouldn't give balance much concern. But given the gears in it are stamped steel and the brake just an overrun clutch on the motor shaft, I would lean towards making the assembly as balanced as possible for long term durability. Seems though if I were dipping my toe into EME the gain of a 2nd yagi on the other side would not be wasted, solving the balance issue at the same time.
Mark K5LXP
Albuquerque, NM