2017 Ultra computer problem ?
I don't think the OP did anything wrong. Yes, you should vary the RPM's but the cruise should work fine and not effect anything mechanical or electrical.
Is another dealership available or an Indy that is authorized to do warranty work? I've had the same issue with service writers before. They can be clueless. Keep in mind they are not mechanics. They are customer service agents/salesman. They are there to great you, fill out the paperwork, then try to sell you additional services. Nothing more. All they know is what the mechanics tell them to tell you.
Good luck.
There's nothing saying you can't use the cruise control during the 1000 mile break in. You don't break in the electronics. The ECM needs no break in period; it has no moving parts. The varying speed requirement is for the engine. Seems to me the dealer would have "used" the cruise control and everything else as part of the pre-delivery inspection you paid for.
My first wife and I married young at age 19. We had not been married long and were driving somewhere when I accidentally hit the horn button. She looked at me and asked why I blew the horn. I hit it again and held it four or five seconds. Then I looked her straight in the eye and ask if no one has ever taught her to clean the electrical system on a car? She replied no and I explained that it is important every couple of months to blow the horn real good to keep the electrical system cleaned out. Well some time later she was driving and all of a sudden she hit the horn long and loud and looked at me so proud that she remembered!
That marriage did not last.










