I did. When we folded less than two years later, one of the CTOs biggest stated regrets was that he went with Firefox instead of Chromium. The extension story in Firefox was easily 10x harder. Interfacing with the OS as well. Getting dbus services to work was a fool's errand.
Thunderbird also works.
I happen to own a brwoser extension and have both chromium and Firefox extensions. I kinda know myself.
GNU/Hurd is also a very interesting alternative OS, the design is a lot more elegant than GNU/Linux, it's still under active development and it has a surprising number of active users.
It's still a very bad idea to build the foundation of your tech stack on it.