@drtritm: In addition to the magni software, there is a separate roscore process running at boot.
You can disable it with sudo systemctl disable roscore.
If you want to change the ROS_MASTER_URI, make sure you set it after the source /etc/ubiquity/env.sh line in the .bashrc.
Thanks for linking that page Mark. There are a couple things missing that we should add (issue open https://github.com/UbiquityRobotics/learn/issues/13).