(Robin Uses a pistar Hat Hotspot (single antenna) set in duplex mode so he can set TX and RX (Reversed) Frequencies in his situation..)
In our working situation running perfectly since September 2020
If the Tait hotspot is TX up to the repeater the FTM-100 is RX from the Repeater.
If the FTM-100 is TX up to the Repeater the Tait hotspot is RX from the Repeater.
There is NO loop as TX + RX are Different..
Repeater TX = 146.750 Mhz RX = 146.150 Mhz
FTM-100 TX = 146.150 Mhz RX = 146.750 Mhz
Tait Hotspot TX = 146.150 Mhz RX = 147.750 Mhz
Therefore if a Mobile station TX to the Repeater The FTM-100 and the Tait hotspot both RX and pass to (WiresX room for FTM-100) + (NZ-Canterbury-NZ Reflector for Tait Hotspot)
If someone connected to th NZ-Canterbury-NZ Reflector TX the Tait Hotspot will TX to the Repeater The FTM-100 will RX from the Repeater and pass to WiresX and the Mobile Station will RX from the Repeater.
If someone Connected to FTM-100 WiresX room TX the FTM-100 Will TX to the Repeater the Tait hotspot will RX from Repeater and Pass to NZ-Canterbury-NZ Reflector and the Mobile station will RX from the Repeater.
My Tait Hotspot is using a F5UII MMDVM (kitset) on an Arduino Due board connected to a Raspberry Pi 3B
Running on the Raspberry Pi 3B is MMDVMHost + YSFGateway and also the NZ-Canterbury-NZ Reflector. (not Pi-Star).
I hope this brings the workings clearer to you Ben.