Well, for now, that's not going to be an issue. I suspect I will still be testing Big Sur when V11.2 is released, and thus will download the complete installer file, and proceed with the installation when I am good and ready.
Given the level of control you appear to want, I have to wonder why you aren'r running some form of
Linux or
BSD Unix instead of macOS? That way you could download the actual source code make any modifications to it you desire then compile and run at your pleasure. You could include only the functions you use and leave all the other "stuff" out. You would have a totally customized environment and applications and there would be no App Store or any controlling agency other than yourself.
While I used to be a software developer in my working days (quite a while ago), I don't want nor need those headaches! And for the Mac OS, it's the way I have always done it (unless for those instances where I just download and apply the Combo installer. Looks like that option, however, is going away).
For just about all of my third party apps, though, I take the upgrade route (Onyx is the only exception, as they have a version specific to each Mac OS).
