I have a DXE 4sq for RX/TX. RX model is probably similarly controlled, by 3 DC signals.
I am confident, that you could use the available outputs in RRC followed by relays. In my case, I need one of them for
CW, and with only 2 remaining outputs, I would have missed the omni position. Instead I use one serial port for antenna control, using a Microham stack switch, that can be configured as a 8-position selector. It drives my 40M 4sq and 80M triangle with 6 directions. Microham's webSwitch could be used as well,
and the web is full of all kinds of ethernet relays...bought one from Bulgaria that controls 16 relays, and ended up learning JAVA to modify the user inferface.
It's easier to click a box with wanted direction, instead of thinking binary code and clicking several buttons to get the wanted direction.