Yes, I ended up calling a local Scag dealer.  A couple of the guys there looked around some and found that the 25hp Kohler has a spot on the elbow just below the filter housing for the sensor.  The 29hp doesn't have a location for the sensor.  We talked about work-arounds but decided against.  On the bright side, apparently Kohler makes a sensor I can install; I just won't be able to incorporate it with the Tiger Eye display.