This weekend a took a couple of photo of Laxman's Super's doors. The car was restored by Daron Walker/Vintage Customs and used, I presume, Alfaholics door seals. As delivered the doors were significantly harder to close than normal but didn't require the kind of hard slamming often reported. You just noticed that they took more effort. John had a professional spend some time (think hours) on adjusting the doors and the results are evident in the enclosed photos. The shut lines are perfect and, more importantly, the doors now close without undue effort. When compared to my Super's doors with original seals, the effort is a little harder but not by much: no slamming is required. I regard the adjustment to be very successful, IMHO.
There is, in fact, quite a lot of adjustment built into the design of Alfa's door hinges and striker plates. I've seen this sort of thing done and, if I had infinite time and patience, I could probably get it right. This is fettling of a high order and, if I ever put new seals on my Super, I'll take it to Sammy (the guy in Austin who fixed John's car) and let a professional do it.
A caveat. Not all doors fit the way God and Alfa intended, especially after 40 some years and possibly indifferent care. If, your car has replacement doors, or if there was crash damage at some point then all bets are off about ever getting the door and seals to fit right.