I have found mobile RV techs that come to your rig MUCH SUPERIOR to dealer service.
One reason - they don't get paid until the work is done. Sure there is a minimum, but most of them hate jobs which drag on and on.
Yes, it costs you more, sometimes.
Something else I discovered about dealer service. Most of the time, YOU have to pay the shipping on parts.
These things are not like a Ford or Chevy with millions on the road and major parts centers within a day's drive/ shipping. RV parts often have to come from the manufacturer.