Every boutique I have talked to has not done this after corporate started cracking down on modifying anything.
I think this is the key in this discussion really. Any boutique who is or has done this, is violating Omega corporate policies. You can agree with those policies or not - your decision - but they do exist, and for reasons that Omega deems valid. For example if they fit the clasp, and you are getting on a sailboat in Boston harbor, the watch falls off, and the divers you hired can't recover it, who's at fault?
If fitting the clasp would actually cause this to happen is completely secondary - corporations are by their nature not willing to take such risks (investment banking companies notwithstanding).
In my view as Omega sees a spike in clasp sales for watches that really should not need replacement clasps yet, the light will go off and they will crack down - they may have already started by the sounds of it. I can assure you they track parts sales - I have received calls asking why I've bought so many of certain parts from them for example. And although it was the local country manager that called me, the question was being asked by Omega in Switzerland.
And as noted, if you compare all this to how Rolex (the Big Green bully of the watch world) operates, Omega/Swatch looks like a free for all where anything goes. Just one small example - if I need say a new case back for an Omega, I go on the Extranet, look up the case reference, find the part number, and order it. 1 or 2 days later it shows up at my door - they don't ask me to prove that I have the watch the case back goes on, ask for the watch serial number, or check those claims when they do their next shop inspection, etc., so absolutely zero drama. If a Rolex needs a new case back, the watch has to be sent to them for a full service, and they will install the new case back, and keep/steal the old one.
Lots of Omega fans thought it was great that Omega was going to try to compete with Rolex, but that entails more than just making the watches better and raising prices...it starts to creep into all that they do as a business, which is not something to look forward to.
Cheers, Al