Hi Marco,
I used to maintain papirus-icon-theme so I could be interested on be added to them project to (if I can, as I'm not a Dev)
The project addresses only dev's, but you can prepare PR's and patches and we can merge them.
We are also glad about helping hands in the open bugs. The project page will grow here: https://wiki.gentoo.org/wiki/Project:Themes -- Best, Jonas
