I guess I would call 'em and ask. Any shop worth it's name at least ought to understand the principles behind the desmo service, at least be familiar with the concept. There aren't any other examples of desmodromica in the motorcycle realm that I know of (Mercedes used desmodromic valve actuation in its late '50s SLK line; that's the only other instance I know of).
But if they haven't done it before ... methinks it'd be worth the 50m trip. It wouldn't be worth it to me to let some shop - unless you're already on really good terms with the mechanics - use your baby as their practice mule.
I refuse to bring my Ducs to the local Ducati shop, but there is a local garage I will bring them into when need be. The owner used to have a Paso, and I get the impression that when I do darken his doorway, it's always a somewhat bittersweet experience for him.
But - that's why I'll bring my wheels to him if it's something I don't want to do (and I do my own valve service). There was another shop in the area that sold Aprilia/Guzzi/Triumph/KTM - out of business now 
- that I trusted as well, since the owner had quite the collection of Ducatis himself. So there's where I draw the line: I won't bring my bikes to the only local "authorized" dealer, but I will entrust them to select few outside of myself - providing they're qualified (owners!). 