I have seen similar questions but none with a definitive answer. I host dozens of WP sites on a cloud server (all latest version) however this causes a lot of unnecessary backup activity. I am not a fan of multisite. Really I am just looking to simplify by keeping a core set of files in a central location that can be read by all domains. The preference would be to extend this by allowing versions.
Core > 3.2.1
Core > 3.2.2
then point a domain to the prefered version of central files. This would allow me to backup only uploads, theme and database files.
Wondering if there is some documentation out there on this subject without having to do any heavy modifications?