Ok, because the crickets have chirped in I guess I can also, Im not a painter. But I can do as much as the crickets.
Here is my chirp. Why not paint the entire car in one shoot. Door jambs and all the other jambs and the panels also. Big masking job, you will have to mask the door openings, door panels, engine compartment, trunk compartment, windows, underside, basically everything that isnt gonna get the color. The mask has to be flexible for the trunk lid, engine lid and doors so you can shoot those surfaces. Paint the jambs then close the lids to almost closed and paint the lid's tops.
I dont see any reason why you couldnt paint the jambs and outside panels all at once. It will be a long day, but you wont have any lines (from taping) to deal with.
Like I said before. The masking is the major part of the job. It might take an entire day (maybe two) to do a proper masking. Using flexible plastic for alot of it so you can move the lids and doors. And move them (the lids) so there isnt any loose plastic that will droop and touch the paint before painting just to make sure..
I would spend a good days work masking the car and prep it correctly for the next days painting.
Beats the hell out of trying to blend paint lines, specially with a metallic.
Make a really good mask. Dont forget to think outta the box. Restaurant grade saran wrap really works well for the tight areas and it flexes pretty well. Better than aluminum foil (or paper) which works good too.
Clean the entire car really well, so there isnt any dust, the tape will grab better. Tape the lines off in areas that wont be seen. Like the pinch weld on the rocker area.
I really dont see any reason why you couldnt mask an assembled car off and shoot the entire thing, jambs and all.
There will be areas that you just cant get to. Like the door hinge area and the outside of the inner fenders. The inner fenders, not as much of an issue. They are usually dark, like black anyway. But the area right around the door hinges is a big problem area. Mainly because when you open the door that area can be seen. It doesnt have to be body color for it to look nice. But to be honest, it does look like a better paint job if the area is painted body color. Not gonna happen unless you paint the car with the doors off though, no getting around that. But if you had the doors off and painted it black that might help. VS if it is a light color, like white. Its a dark area anyway, in the shadows, so black will look ok.
The hard part is picking the transion point. Where do you decide the body color ends and the black or white begins. Thats why a door off paint job looks better. You open the door and there is still body color in there, at the hinge area.. But.... Sometimes we cant do it that way. So we look for alternatives.
I am a fan of alternative car builds. Mainly cause I HAVE to go that route sometimes. Necessity does not over rule my bank account. The money comes first, then I figure out what I can do. Some folks have a bottomless account. Not this dude

JR