You want to use a regular “Standard” sized simpleRTK2b or “Micro”?
The Standard AiO v4.2 doesn’t have a dedicated Xbee radio socket, you rather plug it directly into the simpleRTK2b. Just make sure you use a baud on uart2 that matches your LR radio (probably 115200).
The Micro AiO v4.1 has a dedicated Xbee socket that by default is routed to the Teensy which takes care of relaying the data to the “Right” micro F9P but you again you have to make sure the Teensy baudRTK setting matches in the code.
I have the standard sized simpleRTK board with xbee socket used for the RTK radio link, I will add a network shield to this, with the plan to supply power to the ardusimple and receive GPS data to the Standard AiO 4.1, which will have my teensy, IMU and Cytron.
Hopefully I have answered that right, again thanks for the help