The only tab collapse extension that seems to work. But truly agree with the wish you could set a timer for 60, 90, 120 seconds or such before the group collapses.

Great extension. Would be nice if a timer could be included for how long we want the tab group to be inactive before it closes

It works

Why Firefox doesn't do this by default who knows. Makes tab groups usable.

In the words of Todd Howard "It just works"