Okay, I understand the changes. I still give it one star. I would give a half a star if possible. This add-on sucks. Opening multiple windows is NOT a good solution for the loss of the ability to actually tile tabs.
I give Firefox "Quantum" one-half star as well. Who gives a rip what Google and Chrome do? I use Firefox because I don't like Chrome. Mozilla; why emulate a browser you are competing with? Shame on you. Regain your honor and independent identity. Either put the silly thing back the way it was or fix the currently crummy product. When you want to open a new tab, please don't open a new separate window.