Forgot to mention in original post - it seems well understood that the window managers may or may not play nicely with systemd - as to who will do power management.
If a user is not logged in - it is still nice to have systemd sleep system on lid close for example - and for this reason the window managers are given the ability to "inhibit" systemd when they are claiming to do the power management. And when they are not, then systemd does not get the "inhibit". [1]
Several window managers, KDE among them are supposed to "play nice" with systemd in this regard.
So, one suggestion some have is not to use KDE at all for this - and rely solely on systemd - it is of course less configurable. I have not yet tried this approach. This can be done via the same login.conf.
It's not a huge deal, as I just press power button to wake it up again, but curious what others have found.
gene [1] I'd rather have a positive than a triple negative LidSwitchIgnoreInhibited=no might be easier to read as LidSwitchInhibitIsActive=yes
