One of my partners used RTX last Fall on a trial basis.  There is an Insight in that tractor at times that gets its GPS from the Nav II diagnostic port that is connected to the CFX-750.

This normally works fine with WAAS.  I don't recall if he was attempting to use the Insight when he was trying RTX.  I will check with him.

I would think that going through the Nav II port might have a good chance of working.  Otherwise there is the NEMA output from the CFX-750 itself.  Sounds as if Trimble said that wouldn't work.