The latest OSPi software comes with a module for triggering the relay’, and its GPIO is defined internally as pin_relay; but yeah making this automatic with the start of a program would require a lil modification..
It seems like it would be a decent idea to have an option to configure the master station to be the onboard relay though; It shouldn’t be too hard to implement.. maby Dan can help you out as he is the resident python expert, I dont think a module can hook into the interval loop so it would be a hack to the core code.