Handy extension to have....in theory. However,it prevents TreeStyleTabs from functioning,and has a regular habit of locking up absolutely everything on this PC,including Ctrl-Alt-Delete,which obviously means hard reboots are the order of the day.

I'll stick with it for the time being though,as it's still early days for developers trying desperately to clear up the awful mess that the 12 year old Korean kid with aspergers and OCD (zero empathy for anyone else of course) caused when Goog.....erm..sorry....Mozilla presumably employed him or her to wreck the basic functionality of their browser.