I'm building a HO track module now with a similar small footprint controller for a turntable. Clockwise, counterclockwise, speed, and OFF (to ensure output power is really off).
Seems to me your input could be AC or DC, correct?
I see how you described the front AC input for ease of connection, but why not have a rear entry option for the input, keeping wires away from the front?
Electrical Engineer: Retired
Former SEPTA Regional Rail Division electrician