I loved the previous version of this extension as I can have multiple windows within a single tab. It saves window space and less actual windows open.

But this... is not useful at all. It does not have the functionality that I need nor want. I understand that this is because of Mozilla's updates... it's still disheartening.

I implore the developer of this extension to please find a way to create a new one that has the functionality of the previous version.

I rate this extension as a one.