interesting.I'm a big fan of IRD Power Ratchet brake levers. I've got them on my modern steel gravel bike with 10 speed dura ace bar ends and I'm thinking about getting another pair or two for some other vintage bikes I've got. They can take friction or indexed levers and you can run whatever cogset you want in the back.
Gevenalle (formerly retroshift) sells a similar version based on the Tektro levers too.
never seen or heard of them. What are they and how do they work? any photos with them in situ?