I would actually PReFER a good 'third party' that actually is a more seasoned contractor for the type of work involved, since the dealer is obviously saying that they don't have the 'skills' for it... this is often the case for paint work, chassis work, engine or transmissions, since the dealer is less of a 'mechanic' for RVs, and more of a 'repairman' for the house parts.
Now, whether you prefer to let the dealer handle all of this, or take it directly to that specialist, is up to you, since the warranty is going to cover it, either way...
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada.... formerly Georgia, then NorthCarolina, now Alabama : )