I’m in London. You’re right about manufacturer backup so that needs to be taken into consideration. For me the Prosecco is just a leisure bike so it’s not treated harshly and I was happy to accept little or no manufacturer backup. As you mention, Merlin themselves are okay when an issue arises. In fact, I’ve had to return a new bike to them a year or two ago that had a defect and it was sorted out very quickly.
One other thing I’ve noticed on the EX-Gravel is that the inner tubes leak a lot of air compared to the ones on my other bikes. The inner tubes on mine are Kenda ones. I’ve got some 60mm valve Scwalbe ones to try out soon.