I will say, I thought that the OEM gave up the high temperature paint cure with the major peeling problem that they had into the 90's...so I called a friend of mine who would know and this is what I was told.
"In the 70's they used to bake paint at 350 degrees to achieve cross linking...they found out it didn't work well. In the 80's with start of base clear in North America is when they started experimenting with different ways to achieve cross linking at lower temperatures and a more widespread use of catalysts...they found out it didn't work well. Today with the 1K Melamine clears, being baked at 285 degrees they are having a similar situation...it's not working well. Manufacturer's are still paying out claims for delamination at a higher rate than the aftermarket repair shop has claims for adhesion. Consistent adhesion at the OEM level is still an issue and time will tell."
I do apologize, I thought that the ultra high temperature clear bake went away when water born base coat was introduced and more widely used at the OEM level.
However, I will stand by what I said earlier, I will put a paint job done from metal up by a qualified experienced painter ahead of an OEM paint job any time. I know I would get a better finish (less orange peel) I know that the aftermarket has a lower number of adhesion issues than the OEM and because they bake their clear at a high temperature and have done so for many previous years of failure, I don't believe it makes it better...probably faster, but not better.
As far as removing OEM primers on collision repairs, I agree with you Tech69, if it's not necessary to do the repair back to OEM standards, then there's no need. If I'm doing a restoration on an old vehicle with old paint...it's coming off. Not many people are restoring a 13 year old Jetta, but aftermarket clear coat being durable with fewer adhesion problems...in a heart beat...and isn't adhesion part of durability.