SGP Software with Shoestring FCUSB & JMI Focuser

I have exactly the same problem as you, Johnk, although my set is a shoestring FCUSB + skywatcher motorised focuser.
I checked the "absolute" wrench/screwdriver symbol when I installed it but, like Johnk says, "the software seem to simply extend the focuser out and then keeps going unless I get it to stop rather than recognise that it has reached the end of the focus tube".
I will keep on investigating...