I had no
luck because the .xpi link for chrome wouldn't unzip to anything but .xpi
So I installed it in Firefox and I'm going to try to reverse engineer it. It does seem cool.
I'm not sure how you made out but I might be able to help. The .xpi file extension is easily worked around by simply changing it to .zip. Do your work and then change it back to .xpi and see how that goes. I've used that method to edit the files to allow install on lower levels of FF to get an extension to install.
I'm trying to install it in Brave but first attempts have failed.