Yes I agree with your conclusion Leif, blight usually comes when you are just harvesting or about to harvest a fine crop and most is wasted. I succeed only with Sungold against a south wall, they crop from mid July and get less blight from being under the eaves a bit.
This year in a bed I have grown “First in the Field” which is only just ripening now, not first at all! And blight is spreading on both plants.