Benjol
Firefox extension is not compatible with multiprocess
According to the Add-on Compatibility Reporter, this extension is not compatible with multiprocess (a.k.a. Electrolisys) and prevents to enable it automatically.
The way Firefox addons have to be built change to often and rapidly that the build process of this addon could not keep up. I would recommend switching to the user script.
@oliversalzburg I'll note that Firefox, like Edge, are all now solidifying on a spec largely inspired by Chrome's own extension API. So most of that flux is starting to die off, and people have already found that many Chrome extensions just work in Firefox without any modification, and many more others only require slight modification. Firefox itself has made special efforts to ease porting from Chrome, and they also maintain a shim to use the WebExtension API within Chrome.
