>>>> "CD" == CS DBA
CD> I just received a new Lenovo X1 4th Generation laptop
I've had the same laptop for a while. It's great and well supported,
except for the fingerprint reader.
I don't think the resolution chooser will show anything other than what
the panel itself indicates that it supports. It doesn't offer that mode
when probed, so there's no reason for KDE to offer it to you. If you
look in /var/log/Xorg.0.log you should see the list under "Printing
probed modes for output eDP-1". Just a plain xrandr call should show
the same list, and that should be reflected in the resolution list you
can choose in the settings application.
If you can force a mode with xrandr, then you may be able to modify your
X configuration to force that specific mode to be available. There's
some information at https://www.x.org/wiki/FAQVideoModes/
Afterwards, well, I guess there's a fair chance that the KDE applet will
offer it. Adding modelines isn't something that is done very often
these days so you're probably going to have to experiment a bit. And of
course, forcing the panel into a mode it doesn't support is almost
certainly not going to hurt anything.