Send RC joystick commands over eth to drone

I want to use my TX-12 as a joystick input to QGC (or Mission planner) and forward the joystick command over ethernet to a drone (basically fly the drone using a wire, not RF emissions). Is this possible? I tried QGC (and MP) with no success. The attached diagram is a hack I thought of. Using a ground PI5 (green box) to forward receiver outputs (via eth) to a PI5 on the drone (which forwards to the FC uart). Do this make any sense? Any advice greatly appreciated.

It is supported by MavProxy, MP and QGC by using serial(MavLink) over UDP (3) needs to go from serial to UDP for example using MavRouter if your board has Ethernet port you can do that without (3). I would recommend connecting RC controller via USB or Bluetooth instead of USB receiver dongle.