Re: unwanted checks for updates.

[home user]

My apologies for the delay in trying these.  I've been swampd.  You 
know, gotta get the daily fix of "The Rifleman", "Hogan's Heroes", and 
"Rush to the Dead Summer".  :)

Ed suggested
> gsettings set org.gnome.software download-updates false

and
> ... "systemctl mask packagekit.service" is a one time as root command.

I did it.

Ed also suggested
> systemctl mask packagekit.service

and
> gsettings is a per/user setting ...

I did it.

Ed, you may be "not a regular gnome user", but you hit the nails on the 
head.  These so far appears to work.  If it's still fine after another 
few days, I'll tag this issue "SOLVED".  Thank-you.

I hope these changes also turn off automatic *checking* for updates.  I 
don't know how to see if that is the case.