Once I settled on Zorin 16.3 x11 Gnome/Pop Shell for my long-term setup (thank you @Startreker), I set about recreating and revising my keyboard shortcuts. Involved in this process was the integration of Gnome/ Settings/Keyboard shortcuts with Gnome/Pop Shell shortcuts in such a fashion that they cooperated instead of conflicting with each other (it's not difficult, just a bit of time to make the changes.)
This time when I was recreating my shortcuts, rather than accept the default choices, I was more deliberate about choosing keys combos that made sense to me, such as using Ctrl-Shift modifiers for the launching programs. For the letters, I chose whatever made the most sense to me, and fit best with my past habits. (For instance, the shortcut for LibreOffice Calc is Ctrl-Shift-e, for "excel")
I have at least seven commands that use the Super key as the single modifier, something which works fine with Zorin 16, but has become problematic with 17 and 18. Gnome 3.38 is willing to "wait a dang nanosecond" to see if the super key is being used as a chord (more than on key) or a trigger (single key). Apparently 17 and 18 are victims of Gnome's gnomes shaving the reaction time down so much that the Super key is hijacked as a trigger before it can be used as part of a chord. Not so super.
Bored yet? But why? This stuff is fascinating! It's whatever computing can do to make us more productive - how it can amplify our abilities and improve our effectiveness - that's what's exciting. (Back in '88, the first thing I did with my IBM PC clone after I hand-cranked it into life the first time, was to go into Wordperfect 5.1 and make an entire keyboard worth of macros. Ctrl-e to create an envelope on the fly? That was power.
So the shortcuts... it's so easy to make our own combos for everything! There's a great little xfce application called "application finder". Like Gnome, it uses GTK 3/4, and so it functions in a Gnome environment without requiring the full XFCE desktop session; no bloat, just a binary. 
In this app you can find and copy the cli command to fire the app just by right-clicking on the listed app, which is all the info you need to create a keyboard shortcut.
OK, you're dying to know, so here they are:
SYSTEM & UTILITIES
Super -- Zorin menu
Super z -- System overview
Super a -- Show all applications (the grid)
Super s -- Suspend
Super l -- Log out
Super r -- Run command prompt
Super t -- Toggle auto-tiling off (and on)
Super f -- Toggle floating window
F11 -- Toggle full screen mode
Break key -- Restart Gnome/Pop Shell
Print -- Screenshot (Gnome Screenshot)
Menu key -- Window context menu in active screen
CtrlShift s -- Settings
CtrlShift f -- File Manager (Nemo)
CtrlShift n -- Gedit (n for notes)
CtrlShift t -- Terminal
CtrlShift j -- Junk (Trash)
CtrlShiftAlt o -- Force Onedrive sync (Abraunegg app)
CtrlShift + -- Zoom in
CtrlShift - -- Zoom out
APPLICATIONS
CtrlShift w -- LibreOffice Writer
CtrlShift e -- LibreOffice Calc (e for Excel)
CtrlShift p -- LibreOffice Impress (p for Powerpoint)
CtrlShift k -- Google Keep
CtrlShift c -- Google Contacts
CtrlShift a -- Google Calendar (a for agenda)
CtrlShift g -- Gmail
CtrlShift o -- Work Email (Outlook Web App)
CtrlShiftAlt l -- Librewolf
CtrlShiftAlt f -- Firefox
CtrlShiftAlt b -- Brave
CtrlShiftAlt v -- Vivaldi
CtrlShiftAlt k -- KolourPaint
Apps like Scanner, Clam UI, Timeshift, Software Updater, and Spotify I keep on the taskbar and open via mouse. I use them seldom enough that it doesn't affect my work flow.
On a side note, to minimize taskbar clutter, I set things so running apps don't show (Zorin Taskbar/Behavior). I don't click on running app icons anyway. And any running programs I can quickly surface with with Alt ~ . Why Alt ~ instead of Alt-Tab? See below...
CHANGING APP FOCUS
Alt ~ -- Switch directly between all open windows
Ctrl ~ -- Switch directly between windows of same app.
(Super Tab -- Disabled)
(Ctrl Tab -- Disabled)
(Alt Tab -- Disabled)
I made the changes above because there were too many options for focus and window switching for my taste. Also I prefer the direct change options because they are quicker and just as effective.
Changing Alt-Tab to Alt ~ and Ctrl-Tab to Ctrl ~ I did because I like longer stretch. You can't miss the ~ key at the top left of the cluster, and besides, except for occasional use in the terminal, the poor thing has been neglected.
(Note: I realize that the tilde symbol (~) isn't accurate, because that would involve using the Shift key for uppercase. But I use it here to represent the physical key because when I try to type the backtick symbol, a singularly unfortunate term, it insists on doing its markup thing!)
WINDOW SIZING & POSITIONING
Alt Up -- Maximize
Alt Down -- Unmaximize (restore down)
Alt h -- Minimize (h for hide)
Alt x -- Kill window
Alt o -- Re-orient window with that next to it - 4 positions
Ctrl Super Right -- Split monitor, fill the right half
Ctrl Super Left -- Split monitor fill the left half
The two above are my favorite because of the quick and practical control they give me in dealing with the results of pop shell auto-windowing choices. Doesn't matter where the window appears or at what size, a quick application of one or the other of these shorts cuts and I'm back in the flow.
MOVING WINDOWS TO DIFF MONITORS
SuperShift Left -- Move window to left monitor
SuperShift Right -- Move window to right monitor
Super drag-w/-mouse -- Force move to diff monitor if stubborn
WORKSPACE 1 & 2
SuperShift 2 -- Move window to “the closet” (wkspace 2)
SuperShift 1 -- Move window back to the desktop (wkspace 1)
Super 2 -- Navigate to closet
Super 1 -- Navigate back to desktop
Nice to have another workspace if I ever need it. I sure don't need four, but my needs are fairly simple.
Not all of these are instinctive yet, but I'm getting there. It's starting to click. I can see why it's called flow.
