In a manufacturing environment pointy or dog head bolts allow power tools to drive the fastener quicker and better with power tools. The point helps the bolt find center quickly and reduces the risk of cross threading without having to hand start bolts.
I have no idea how Porsche assembled back in the day, but, it's likely Hans held the door in position and Franz drove the bolts quickly with an air tool as Hans complained that it was about time to swap jobs and Franz should hold some doors in position.
Probably rough fit to hold in position 1st and tweaked later.