The tyre centre doesnt know what they are talking about, especially as they are no doubt considering themselves experts. Avoid them.
You can put NonRFT tyre on your wheels. Insurers dont seem to mind unless you change the tyre sizes outside of the range specced for your car by BMW.
My E91 has both 17" and 17" wheels listed in the specifications with dufferent tyre sizes to keep the same outside diameter but same tyre width.
The TPMS doesnt monitor tyre pressures but uses differential wheel revolutions to detect a change in tyre circumference caused by a flat tyre. Change the tyres and reset the TPMS then it should be fine.