Undo/redo gives one selection (ALL), copy gives one selection (NEW), and as far as I can tell, there is no means to keep the original. One doesn't realize how frequently a specific command is used until it is taken away. Keeping the original selected has made several commands more challenging. For instance, I often multiply an object to get equal spacing, even though the original will be deleted - and this used to be very simple. Just another challenge...
As far as mirroring goes, I guess that we were missing the new location for mouse constraints - or someone didn't check what the little boxes were actually referring to...
Primarily, we mirror a copy. So we made CMD-M the command for that, and made mirror CMD-SHFT-M. Just reversed the hot keyes for the two commands, to keep the carpal tunnel to a minimum...
Thanks for your help.
Vito