3 major issues:

* I always need to reload all tabs before mouse gestures work.

* Export settings doesn't work. A new tab is opened and loading forever.

* Open Link doesn't work on images.

This is on Firefox 57.0 on Linux64.

Another thing that's not perfectly nice is that I need the toolbar icon to open settings in a full size tab. Would be nice to get there from Firefox's addon page.

This addon has potential to become great, but still has some problems which indeed make it a Beta. With these issues fixed, it would totally deserve 5 stars.