Looks like you could do the same thing with a Haimer for $200 cheaper. And also use it on your mill. The only difference I see is the cylindrical probe tip instead of the ball on the haimer.
The SPL15 controller looks like it has the DIN connector for the electronic probe. Too bad the PP tool offset screen in lathe mode doesn't include use of this capability, although implementation would be more difficult since you need to probe in two directions.