You can just keep up to date with the software updater, BUT that does not update the actual SM code, those updates are done by downloading the latest version from the SM website and burning the new image to a card and starting again with new image...so that being said there is no need to do that unless you have an issue or you really need the new version as it contains a fix that you may need....
I only have the latest one because I have the newer rpi3b+ and the older version was not compatible with the plus version...it’s only in instances like tnatbyou need to upgrade..
So just use the updater...
Stellarmate OS BETA on Raspberry pi4b
Skywatcher EQ8 pro
Meade series 5000 80mm triplet Apo & Meade 8” SCT (de-forked)
Starlight Xpress SXVR H18, SXVR M25c, Lodestar Guide Camera
Pegasus Ultimate Hub for all USB & Power
Pegasus focus motors on both scopes
There are differences of course in the core code that runs StellarMate. Unfortunately, that is not available via the usual update mechanism especially since some of it modifies the existing system to make StellarMate make the work it should.
The important thing is this: If everything is running as it should, do not update.