If you’re worried about them bugging you, it might happen regardless.
Cinnamon is fine enough for a “fire and forget” installation, and comes with user friendly enough guardrails. Part of the ease of use is due to Cinnamon based settings.
If you’re hellbent on KDE for them, why not just install KDE, and uninstall cinnamon? Whichever KDE flavoured OS you choose is going to have the KDE settings and get them to reach out to you if they don’t get it.
You might also be able to set up a login manager that lets you choose the UI, and just leave both on there. Try setting it up like that on Gnome Boxes and see if they can manage either UI or if you can manage to set it up that way.




















just stick to LMDE and cinnamon.