Sorry Dozy, nothing I previously posted this evening refered to the Gordon Corps video, which I had not watched. I hadn't realised you and HN39 were refering to it in your exchanges about the landing config.
Have now watched the video, and cannot shed any light on which of the two standard landing configs Gordon was using, or why he implied that 15 degrees was about the maximum angle of attack for it. If he was using Flaps Full, I think alpha-max MIGHT be slightly less than for Flaps 3, but that guess is only based on the fact that my FCOM says the Flaps-Full alpha-floor is 14.5 deg - 0.5 deg less than at Flaps 3. That said, the small, electro-mechanical AoA indicator seems to exceed 15 deg occasionally in the video.