Hi, I happen to have purchased an RHD double butterfly deployant in order to save a breitling strap that was way to long for me.
I also happen to own a nomos metro as well

The RHD deployants are meant for thick straps, ie. 4mm thick. This applies to the complete range of sizes: 16 mm - 24 mm
If the nomos orion has a strap as thin as the metro, which is 2 mm; then I'm afraid the deployant may be too thick/big and not be a good aesthetic fit for the watch. As in, it would look too bulky.
On the quality side of things, the RHD deployants are solid.