I believe Krown has a different application for surface rust based on their price list but I would not bother. This may give Jeep Chrysler the excuse to wash their hands off any surface paint issue during warranty period.
Excluding issues due to external source such as stone chip, surface rusts indicated a manufacturing problem in treating the sheet metal and no rust protection will help us.
I don't want to sound like I am promoting for Krown but I have read countless pages of Krown-related postings online and there were people who had the same preference of cleanliness in the engine bay, they ended up asking the Krown guys not
to spray the hood ( then the Krown guys forgot the request).
The crimped edges on our Jeeps are very interesting, have you looked at them closely? My Mazda experience made me do this.
The horizontal edges at the bottom looked like they were double rolled then folded; the paint finish made it look like no seam at all, I was impressed. So I think we need to apply a paint protection that will shed moisture away at the same time.
The vertical edges were folded so technically moisture can still penetrate from both in and out direction so it needs a protection that seals. A protective barrier from both inside and out should work the best.
The inside of the edges can only be accessed from inside the door panel and again, we depend on the manufacturing process. If any gap there, only an oil film can form a protective barrier against moisture.
In summary, protection by oil film sounds good in theory but we will have to put up with drippings and annual application.