dryfly,
My "break out" box is a 50 amp plug that goes to a little tiny breaker box. L1 is a 30 amp outlet with a 30 amp breaker, and L2 is twin 20 amp outlets with 20 amp breakers.
I've equipped my Class C with two auxiliary shore power cords. In winter I can use them to power extra electric heaters and in summer I can move the electric water heater over. That's done with male and female plugs, so I can move to OEM wiring configuration in a few seconds. Similarly I can wire around the hybrid inverter/charger.