It's great to know it!

As far as I know, only the thumbnails feature is part of the official kde
repo. The rest of the features can be found on the
plasma-appimage-integration extensions set (
https://www.opencode.net/azubieta/plasma-appimage-integration). I guess
that it will worth the effort to explore whether it should be upstreamed or
not and how.

We already have this AppImage Thumbnailer for KDE, it may require some review: https://github.com/azubieta/KDE-AppImage-Thumbnailer