Steve,
I am finally getting around to checking out nexusdrxpi_20210813RC2.img. The first issue encountered is one you may never have encountered since I started up the image sans keyboard and occurred while another computer of mine was booting too which I initially attributed the issue. In short, the Pi folks have added a
new audio prompt to their install setup.
I am currently sitting here waiting for the Update Software process of my initial OS setup to complete. It's taking its own sweet time it is finished downloading and installing, starting around 0805 and finished at 0814. The process said system was up to date so I performed the restart.
Before I did anything else I was going to address the libax25 issue you'd reported but when I ran "sudo apt -r libax25 and ax25-tools ax25-apps" none of them were installed and the /usr/local/src/nexus/nexus-rmsgw directory was missing.
I then went looking for the Raspberry > Hamradio and it was absent. I've got to run now but will start over from the very beginning and will re-download and decompress the xy compresse image and install to a new card unless I hear something different from you before then.