Is there another Volvo dealer that you can take the car to? I've never heard of any Volvo dealer telling customers to take a newer Volvo to an independant as they ALL know that ONLY dealers have the required equipment, like the VADIS PC with break-out boxes, all manuals, wiring diagrams, latest online technical bulletins, Volvos tech support and mostly (supposedly) trained and experienced techs.

There's little chance that any independant shop is likely to fix your car IMHO. I've also never heard of "traveling experts" in the US so I have no idea what that is but it surely sounds like BS to me.
In the US, when you call the Volvo roadside # all you get is a local tow truck driver who knows nothing specifically about Volvos except how to change a tire or jump start a dead battery. That guy is NOT a trained Volvo tech by any means.