Moving baseline setup and output strings

I see from comments that moving baseline mode is available on reach modules.

Do you need to set the distance between the antennas anywhere? or is it computed automatically?

I am more interested in computing an accurate “relative” range and bearing between antennas and not too concerned with “absolute” position acuracy. (my base would be moving anyway)

I would like to output the computed range and bearing from the rover. (Ideally two rovers outputting range and bearing from 1 base station) over wifi or uart.

I had no luck with my ublox 6 receivers using rtklib and I’m hoping reach would fit the bill.