Hi, sometimes I find myself closing >100 tabs clicking and clicking. One feature that came to my mind would allow right clicking on the close tab button and have some options like in Safari, see mock-up:
Option-click the X-button to close all tabs except for that tab.
Also, working with > 100 tabs can be quite confusing. You can use Command-F to add glyphs by name to an existing tab. I rarely have more than 10 tabs open at once.