Agree with recent comments. That is, the loss of some features, after the most recent update, is disappointing. But I will continue to use the add-on.

NOTE THE REASON FOR THE CHANGES ... limitations caused by Firefox's recent update to "Firefox Quantum" v57.0. This update changed the way add-ons/extensions are handled by Firefox. Explanation here: https://support.mozilla.org/en-US/kb/firefox-add-technology-modernizing?as=u&utm_source=inproduct