Basically nothing yet.
I had envisaged it to be able to drive a polar-scope LED, or RDF. There is a command in the skywatcher protocol that could be used for that, but I don't think EQMOD implements it.
If I ever got around to using it for something it would need to be on pin 10 of the Mega to ensure consistency in the code - specifically to be on the same timer output as the ATMega162.