@jon you can edit the dds via updating systemctl service file and point it towards the serial UART instead of a udp socket/port - the og looks like this:
[Unit]
Description=voxl-microdds-agent
SourcePath=/usr/bin/MicroXRCEAgent
After=network.target
After=multi-user.target
[Service]
User=root
Type=simple
ExecStart=/usr/bin/MicroXRCEAgent udp4 -p 8888
[Install]
WantedBy=multi-user.target
You would replace the -p with whatever flag is used for serial and then put /dev/ttyHSX (X number depends on which uart you are plugged into) - you will most likely need to put in a baudrate as well. This file is stored in /etc/systemd/systemd/voxl-microdds-agent.service.