On the Fendt we did install both antennas to test the radio base station as well as NTRIP.I saw on your video posted above that Fendt also has radio antenna and mobile network antenna. You use radio in UK?
I can agree with you that FJD is paying attention only on profit letting everyone to sell. On this way they make a bad marketing for dealers which are honest and do their job right.
Anyhow, you shouldn't be worried about them. Bad news are spreading so fast. At the end, customers will come to you by themselves.