To be fair, most dealer wrenches have little or no experience working on antique K bikes. They do get training on the newer BMWs but seldom, if ever, work on older bikes. Most service managers are aware of this which is why they usually don't like to work on the older bikes.
Indy wrenches like Lior and Mick Vallantine started their careers working on these bikes and generally have a lot of experience with them.