I'm sorry, I'm no pro but what you've been told by the so-called detailer sounds very iffy. Sort the holograms so they don't come back??? A full correction detail would be at a pro detailers for 2 days.
Sounds like all he's going to do is get the polisher out and probably no prep. Put it this way if you get a pro to do it, prior to the correction the paintwork will be fully prepped and decontaminated so no risk of pushing embedded contaminants into the paintwork.
I would give the dealer and his 'hobby' detailer a wide berth.