You seem to be trying to access an undefined variable at line #92 of extension.js which causes some instability when the setting is toggled. Aside from that the extension looks good enough to approve, although it certainly had some issues when I test drove it. Please fix that issue and I will approve.

Thanks for reviewing, The signals should disconnect properly now, I've also fixed some other issues while I was at it, all in all it should work a lot better now.