Also: how/where should I find these settings in a GUI
context?
They don`t seem to be available in KControl. OK, hold on... I think I
found them, in "Desktop"::"Window Behavior"::"Focus", under
the
section heading "Navigation". I tried turning "Traverse windows on
all desktops" off, hitting "Apply", then turning it back on again and
"Apply" again, but it did _not_ seem to help. :-(
Like Mike already
said, this is the setting you are looking for. I tested it on my machine (Debian
10, TDE R14.0.9) and it works in such a way that when I switch windows with Alt-tab the
switcher
shows the list of windows on all virtual desktops, with applications on a different
desktop being
prefixed by that desktop's name - see attached screenshot. The setting takes effect as
soon as I
press 'Apply' button - no need to log out and log in again.
Janek