Feature Request / Idea / Question: Tab Group Collapse/Expand in tab bar

[n00b42]

Just asking if something similar is currently possible to implement at all using Firefox Addon API:

Similar to the way chrome implemented its tab grouping: Show all groups (or optionally some of them) at the same time in the task bar (only seperating them in color/container), but allow to collapse groups, leaving a placeholder for that group to expand it again.

[rtxa]

This for me is the key to improve user experience with groups 🙌 I would like to add that the name of the group can be displayed even if you collapse them.