If the clear flows out like it should, the peel will be minimal, and will sand out with 1500. If your talking about peel in the clear, then yes, that can be sanded out. When you finish the 3 base coats, you shouldn't have peel. Sloppy and inconsistent orange peel is another issue and one that would be cause for one to question the actual quality of the paint job. If you have orange peel in the base coat, then something is wrong.
Orange peel is not a bad thing nor is a totally smooth surface, it is just a matter of preference. While BMW claims that the basecoat is formulated to work with the powder clear coat, the resulting finish doesn’t seem to show it just look at the final product. Most production cars have some orange peel and about the only time I see a totally flat clear coat surface is on custom hot rods that have had custom paint jobs and on exotic cars. BMW exclusively powder coats the clear coat onto their cars, using an advanced clear called Enviracryl by PPG. How long do you think the finish would last in the hands of the average driver Remember, sanding and buffing the clear coat reduces the thickness of the coat. I have grown to like the orange peel in Bimmers, as I see all makes of vehicles and personally feel there are some makes out there that look real sloppy and it makes it difficult for a body shop to sometimes duplicate the "peaks and valleys" and over all sloppiness. In the Auto Body Industry, it is just a known thing that BMW likes orange peel and I know Techs that work in their Certified Collision Repair shops and they go to great lengths to preserve and match factory orange peel, when refinishing repairs. This is normally a result of using too low of pressure or not reducing the paint enough. Using experience to apply clear in the right amount and at the right time after the base coat, to leave them with a surface that will require minimal sanding, to match the factory paint job. An orange-peeled surface has the appearance of an orange peel. A body shop matches orange peel more in an artistic way. Probably a factory Paint Tech deals with this issue and it differs for each manufacturer. But the truck has nicer paint then the Vette. My 15 Silverado paint has some orange peel, havent seen a any new car without it to some degree. I have a 16 Corvette and its true, terrible orange peel, supposedly from the composite panel prep. I personally have never inquired about specs/tolerances for orange peel, though I am sure it exists. Head on over to Corvetteforum and see all the complaints about orange peel.