@n2o1138 said in New Tab Stacking mode:
Closest you can get currently is Two-Level, but it would make more sense to me to use 2 edges than to use 1 and subdivide an area that's already cutting off most of the tab title in most cases.
Your suggestion would still use up more display area than necessary when you don't need the tabbar. A better solution is automate floating vertical tabbar. This GUI will use no space to very little space when you don't need the tabbar, saving most of the precious display area for the webpage display. Here are some examples how it looks:
Hide the entire tabbar when not needed, point at the left/right edges to reveal the tabbar:
alt text
or shrink the tabbar into just favicon when not needed:
alt text
I think it's best when the tabbar is shrink into just 2 columns of favicon width for stacked tabs.