The serial protocol document mentions RC_VIRT_MODE_SBUS and RC_VIRT_MODE_SPEKTRUM, but how are these selected on the GUI and where is the SBUS or Spectrum receiver connected? Is this only for (BOARD_VER >= 30), what is this version 30 or is it 3.0, are these boards available?

(On GUI the RC_ROLL_pin mode does not give option to select SBUS or Spectrum. I guess SBUS could be connected to the RC_ROLL_pin)