Not being funny here, but what would you do if you received your car with the multi-function wheel fitted and the circuit board controlling it malfunctioned?
You would send it in to your dealer for repair/replacement right? And the process they would carry out?....It would be exactly the same as retro fitting the circuit board and new steering wheel.
All the same steps would have to be taken, all the same trim would need to be removed. Hell, read that "How to" on vortex and you'll see you have to take the steering wheel off just to remove the lower ignition cowl or wiper stalk (exactly the same as in a mk4).
This will be a very simple task for an experienced VW technician, and I would certainly have no hesitation in having this done if the dealer is agreeing to meet the additional cost of retro-fit because of their mistake.
You trust these guys to build the cars in the first place, and then service them - this is surely a walk in the park? (or am I missing something?)