Another Tab Groups user here.

Between Tab Groups and Tab Mix Plus for a multi-line tab bar I have to seriously redesign my workflow.

I could live with Tree Style Tab if it could nest tabs on the horizontal tab bar. I run FF on a portrait 1200x1920 screen and the vertical sidebar takes up too much space.

The TagGroups is so part of my daily basis that I went back to the v56.0

I cannot stress enough how it helps me to switch between contexts. It's one of those things that you just did not know that you needed so much.

What options do we have?

None that I know of. What helped me the most about Tab Groups was not just the tabs organization, but the face that I could create regular expressions so that a new page would automatically open in its own tab group (and everything else in one 'Default' tab group). That was a killer feature!