The G-06 movement in the Principia and the SA-30 in the Sirna were both developed by Strehler (as well as the Vianney Halter U30-A). He’s a busy man - also developed the HMC 341 for Moser. Here’s a link to an interesting article -
https://watchesbysjx.com/2019/09/andreas-strehler-custom-travel-watch.html
Not easy to source his high horology works - maybe someday!😉