"Can't argue with that these guys build them."
You are right. There is no argument. The valve check is scheduled at 10,000 miles per any Rocket manual you want to read, and it is stated that way, just like the oil change interval. It never changed and probably won't. Who you talked to and what they said is irrelevant, unless you have a service bulletin from Triumph stating otherwise. How and when you want to check yours is totally up to you though. But the fact is that the factory service for the valve check is 10.000 miles. No argument.