Is the software involved in the APT-GET UPGRADE ( The Respositories) the same for Stellarmate,AB and Std Ubuntu Mate RPI. Only in reference to INDI /Kstars/Ekos and excluding NIGHTLY or specially modified by an individual.
speaking of which, @knro I just tried updating StellarMate 1.3 - which I have been using without problems since its release - with the update link and it failed and subsequently corrupted the OS. Couldn't even boot it. So I just burned 1.3.1 onto the SD card and that's working. The StellarMate update has rarely worked for me.
Astroberry is using official Ubuntu Mate repo and stable INDI/KStars repo. No custom/proprietary repo is configured in default configuration. I do not maintain separate repo for binary packages included in the system.