From my research the remote start fob is also a different frequency. 433 MHZ for the non remote start model and 315 MHZ for the remote start key.
I have used Forscan and enabled the remote start in the IC but have not updated the antenna with the remote start model.
I was a senior master Ford tech for 26 years and in theory it should be able to be done with software but I haven't made it there yet.