KMII[Montblanc Moderator]
51102
My Breitling Aerospace from 2000 or so didn’t have an issue with machining a relief case back 😉
I do agree that the old style case back might have added 0,1mm to the thickness but then Omega still had plenty of room to play with, as the watch in spite of its WR is anything but slender 😉
Don’t get me wrong - I understand that watch brands need to look for cost efficiency as they are businesses first and foremost.