pkcon/zypper remove packagename
does not remove the configuration files that come with the installation (if not explicitly coded in rm scripts).
And with RPM there is no method like
apt-get purge xxx
which not only deinstalled but also cleaned up config files.
iirc on TJC I had some exchange regarding this topic where as output came up a script to do so…
This is missing feature in RPM packaging, in my eyes.
Nor will files created on first start of app be removed.
So if you really want to clear up you would need to hunt down.
In user home .config
probably /usr/share/package
or /var/lib/package
or even /etc/package