Maybe there is a slight difference in the UPO 45 vs 42mm fitting of the newer type straps, I guess we can't say much about the newer rep strap for the 42mm as it doesn't exist yet

but the gen straps goes well, a little overlay, but doesn't seem to ride as high as the rep strap on the 45 which sunny shows, seems to touch the edge of the bezel teeth on the 45?
Also the gen straps are hard rubber, very rigid, are the rep straps soft as described?
It's the hirsch medici type strap I couldn't live with on the POs, I see them a lot in pics, always have a big gap next to the lugs. Nice straps but never saw one fit snugly upto the curved lug.
Anyway noob are supposed to be releasing 20mm straps with their 42mm, that is if the watch ever gets off the ground!
Gen 20mm 8500 strap, gen 42mm 2500 PO.