At the point the desktop settings are going to be reset anyways …
Might as well do all the steps outlined in the archwiki above:
cd ~/.config
for j in plasma*; do mv -- "$j" "${j%}.bak"; done
rm ~/.config/Trolltech.conf
kbuildsycoca5 --noincremental
And maybe the cache too?
rm -rf ~/.cache/*
plasma things in .config will be backed up with .bak appended to the filename.
When you are confident you dont need them anymore you can remove those files as well.