This extension is fantastic and perfectly fits my needs because it allows me to easily switch my navigation context:

close navigation context:
- right click on a tab
- bookmark tabs to the right
- create a bookmark folder
- ok
- right click on the tab before
- close tabs to the right

restore navigation context:
- open bookmarks
- select the folder
- select bookmarks
- open all in tabs

To me it only lacks two options:
- a "close tabs" checkbox in order to save and close them at the same time (I know that Firefox has a "close tabs to the right option", but it does not have the ability to stop at some point)
- the ability to easily deselect tabs (multiselect, right-click on one item + unselect tabs below): this would enable to select a bunch of tabs in the middle of the bigger bunch of tabs (today I had 3 navigation contexts: maybe 200 tabs total :-)).

Thanks!

PS: in my opinion Firefox tab groups have failed because they tried to have a "visual" interface that was useless if you had tens of tabs in each group. This feature would have survided if it has been designed the way you just did it with this extension.

PPS: here is the French translation in case you are interested :-).

Bookmark tabs to the right: Marquer les onglets à droite (it is a variation of the tooltip of Firefox's Star icon used to add a page to bookmarks - "Marquer cette page" in french, that can be translated to "mark this page")
Bookmarks: Marque-pages
Name: Nom
[Folder Name]: [Nom de dossier]
Folder: Dossier
Add bookmarks: Marquer ces pages (the plural version of the tooltip of Firefox's Star icon to add a page to bookmarks - "Marquer cette page" in french)
Cancel: Annuler