Originally Posted by MG2009
So . . . . Unless I plan to do #6, there is no point in doing anything other than simply upgrade to BIG SUR (i.e. using the Apple ICON/System Preference/Software Update menu)?
That is the approach I have taken for several years now and as far as I can tell it is safer and more reliable in MacOS 11 (Big Sur) than it ever was in MacOS 10.x.
Originally Posted by MG2009
P.S. I would do #2 and #3 in a case where I was selling or discarding the iMAC?
Yes, but stop an power down at the point where the system prompts for your language preference. Let the new user start there just as they would if the machine was fresh from Apple's orchard.

Make intentional errors —
Otherwise the Great Spirit realizes you have fulfilled your purpose on earth.

— Navajo saying