Have you looked at the Hadabot for a small hobby ROS2 learning platform? Running ROS2 from the web browser based bash terminal
Also, @Humpelstilzchen have you seen this package from Greenzie https://github.com/Greenzie/boustrophedon_planner
The ROS-Agriculture group has an automated lawn tractor project here: https://github.com/ros-agriculture/ros_lawn_tractor Open for collaboration.