If this is truly a shed and not a barn, I see little reason why 3.6 KVA is not going to be enough (a 15a 120/240 #10 multiwire) but without changing a thing except the voltage drop concern, real or imagined, and a breaker, that could easily be a 20a multiwire, 4.8KVA or even a 7.2KVA feeder to a small panel.
My 230a buzz box welder has been running happily on a 30a circuit for 40 years.
We never determined the actual anticipated load here.
The NFPA wrote that single circuit rule for exactly this, a person who just wants some light and a receptacle or two out in their shed.
I understand we like to sell bigger and better but that does not accomplish much if the guy down the street gets the job by selling the customer what they asked for.
