Like monopusher chronographs?

[Ichiran]

https://revolutionwatch.com/the-comp...-calibre-2310/

I didn't manage to find much info on the RD28 but here is an article from Wei Koh on the history of Lemania movement where there are some insights to Roger Dubuis' rights to produce the movement in-house:

"He (Roger Dubuis) created his Lemania 2320-based* chronograph in three sizes — 34mm, 37mm and 40mm** — demonstrating the remarkable design adaptability of the movement. His Lemania movements received the Geneva Seal and were certified as chronometers by the observatory at Besançon. They are designated RD56 for the regular two-pusher version and RD65 for the monopusher version. I believe that Roger Dubuis was the only modern watchmaker and brand to make a monopusher version of the Lemania 2320.

Dubuis used the movement in other models, including his baroque Sympathie case which was combined with the double-retrograde perpetual calendar, and notably, the Easy Diver Chronograph, making it the only dive watch to receive the Geneva Seal. OK, here’s the important thing about the 2320 movement found in the Roger Dubuis watches. Dubuis managed to secure the rights to produce the movement in-house. In 2008, when Richemont Group bought Roger Dubuis, it obtained the rights to produce this movement."

* The Lemania 2320 is closely related to the venerable 2310 but included a swan neck regulator, 4 extra jewels (21 total), and other refinements.

** There is a gorgeous pic of a Roger Dubuis Hommage Chronograph H40 in the link. Enter at own risk.