I love this addon. It's easily one of the best I've encountered.
If I could just make one request, however, it would be to add the ability to resize columns. This would put the app over the top.
======= Addendum on 2018/04/21 =======
I stayed with FF 56 for as long as I could so I could keep using this addon, but I've been forced to upgrade to FF 59 for other reasons. In your updated introduction, it looked as if there might be a way to enable this addon by disabling multi-threading. To the best of my knowledge, I've disabled multi-threading--though I still do see a second process in the Task Manager. Is there a way to force this addon to be enabled in FF 59 so I can see if it will work well enough?