Forward Mavlink message from companion computer to QGroundControl over radiolink

Hello!

I have the setup shown below:

Untitled Diagram.drawio

I need to occasionally send some data from the CC to the GCS. Since I haven’t found a way to do this using MAVROS, I tried creating a small Python script with pymavlink to forward the data using the NAMED_VALUE_FLOAT message.

However, I haven’t been able to make it work. These are the options I’ve tried:
1.- Since MAVROS is connected to /dev/ttyACM0, I can’t connect directly to it via pymavlink—they conflict over the port.
2.- I tried using MAVLink Router with the command mavlink-routerd -e 127.0.0.1:14551 -e 127.0.0.1:14550 /dev/ttyACM0. I can connect to the data with MAVROS using port 14550, and I can send MAVLink NAMED_VALUE_FLOAT messages with pymavlink on port 14551. Even with this setup, the messages do not arrive at QGC.

The only way I made it work was using the command mavlink-routerd -e 127.0.0.1:14550 /dev/ttyACM0, then connecting MAVROS to port 14550 and pymavlink directly to the serial port. This only worked if I set mavutil.mavlink_connection(device, source=1, source_system=1) in pymavlink. This solution seems very sketchy, so I’m asking for your advice.

Can anyone guide me through this problem? I’m sure my setup is quite typical, but I haven’t found any resources online.

Thanks!