I did the first service on my older Rocket Roadster. Informed the dealer I'd be doing it since I lived so far away. They stated so long as I used Triumph approved oil and filter... no issue. I bought the stuff from them so there would be no issue. The older models didn't really require any ECU updates though and no recalls on the 2012 and up models... Saved myself a bundle both on travel and service costs.
On the newer model, I would ask the dealer to perform any updates/recalls before I picked it up then ask if I could again perform my own service. The only issue is the need to reset some kind of service reminder that some have commented about on the newer model. How to perform the reset without the dealer???