Hello,

I get a RAZER CYNOSA CHROMA keyboard and Plasma-5.19.5 running.

What are the most appropriate choices when configuring Keyboard model in System Settings / Hardware / Input-Devices / Keyboard

If the manufacturer doesn't specify any compatibility, use the Generic keyboard with the same number of keys, that usually works quite fine.

Any specific settings that depend on a keyboard driver would need the manufacturers driver anyway, so check their website.

Mamarok wrote:use the Generic keyboard with the same number of keys, that usually works quite fine.

Thank you Mamarok for taking care of my question.
You are of course correct (and wise) suggesting the generic keyboard.

However,

Having the generic keyboard selected, I had spent some time and in vain, trying to activate the org.kde.powerdevil.backlighthelper dbus service.
I incidentally dreamt that selecting some more dedicated keyboard could do that automagically for me...

I fear that this kind of features are probably no accessible through the keyboard profiles, looking at the list there are no recent keyboards listed. Most of these profiles only handle some specific key positions that might differ from a generic one. You can try your luck with Cherry, Logitech or the like, but I fail to see which of these profiles refer to a back-lit keyboard