The below guide shows that I can rebrand the desktop edition (Windows). Can I also rebrand the cloud version or server version of Manager and how to do that?
Most likely not. While some of the same techniques work, because of the way the desktop edition for Mac works, it is not possible to completely rebrand for Mac without hacking macOS itself. You end up with residual identification as Manager in various places, rather than your private brand. Therefore, no instructions have been published.