Lo probé y por ahora fantástico ADEMAS te la abre en la zona de pestañas que cerraste (es decir que si te gusta "agrupar" tus pestañas esto esta buenisimo). LOVE IT <3

Ctrl + shift + T does the trick, but this extension still saves me tons of clicks by keeping a list of recently closed tabs, just like with how Firefox let's you hold the back button to go to a specific site in history (one of my favorite features).

This is the best of the "Undo last closed tab(s). Should be part of Firefox. Thank you.