SS thinks I am attempting to assert myself as the voice of authority. I reluctantly admit he's right. I, and I alone, have devised the only method of soundpost fitting and setting that really works. Everyone else is ruining instruments.
Seriously, though, I find that if I file a very slight chamfer around the post's ends there is a much lower chance of pulling out chunks of top when moving the post around. Also, turning the post a degree or two can sometimes help it settle right into position. When I mention a slight chamfer, I'm talking perhaps 1/4 mm. Sometimes I see posts where the chamfer reduces the touching surface to half or less its original size!