Time to type..... Voltage drop is a FPN in the NEC, 2% feeders, 3% branch for a total of 5%. But, it's a FPN, not 'Code'.
That said...thanks to Ito for doing that typing.
Kale: The buck/boost solution is only recomended (IMHO) with a constant load. If you size the B/B for a 50 amp load, and it drops to 10 amps, you can/may get an overvoltage situation at the 'load'.
