I’m interested in Beaglebone products too, less so the older ones. The AI-64 looks quite capable: Beagleboard AI-64 ~$100 it recently started supporting Ubuntu22.04 so it’s probably more viable for ROS now. There is also Yocto for it I think.
That said have you checked out Hadabot - ROS 2 Lessons and Build Instructions
Or for 4x4 or Mecanum: GitHub - robofoundry/linorobot2_hardware_hippo_esp32_fix: A fork of linorobot2_hardware with support of esp32 on ROS2 Humble and other devices