On the shorter rakes, half the ballasts would be turned so that the hopper doors would discharge evenly. 5 left, 5 right etc. Plenty rakes ran single sided though,and I've seen up to 24 run in a rake, though it's not likely as a working movement. Possibly a stock rearragement.
P.s personally humbled by the positivity shown toward this project from such a dedicated community. Looking forward to meeting a few of ye tomorrow, to have the craic.