Wille just sent over this photo of our front door and it's looking even worse than I had thought. To quote him directly, they're "real crap". The doors close and seal OK but it's the facings that are really faulty, and they will only get worse with the melt/freeze cycle we'll see over the winter.
As I had posted earlier, Wille has spoken to Stefan and new doors are in the offing. I have forwarded this photo to Stefan for his discussions with the door provider.
UPDATE: Stefan has replied with: "It should not be like this, I come back to you with a solution as soon as I have talked to Designa Doors."