I'm using the Techno driver with Mach3. I fiddled a bit with this problem, but the best solution I came up with is to edit the G-code.
After the last Z lift, I add the following:
My table is set-up in mm and I send the X and Y near home, with the Z still at the position of the last lift. This Z position is high enough to clear fixtures, clamps, etc. Then the G28 nudges the X and Y to home and runs the Z down.