I agree - I am running my own Samba server and I don't think I'm affected, but it isn't really clear to me how to double check or why Apple's new default broke things in the first place
You could create a timestamp file on your Mac, where your Mac adds a timestamp per day or hour and have a script check that the timestamps appear in your backup.
You could create a timestamp file on your Mac, where your Mac adds a timestamp per day or hour and have a script check that the timestamps appear in your backup.