Robertm, I too had been thinking about ways to reduce the heat in the corner, as least some. I originally was considering some kind of shield. I then went in your direction, trying to block some of the burner. I finally came up with a very simple and elegant (IMHO) solution. I have already implemented and tested it, but haven't had a chance to try it yet on pizzas. I will take some pictures and report results when I get back in town this weekend.
What I did was find some steel finishing nails that just slide into the holes in the burner tube. I cut a couple dozen of them about 1/4-inch long. Then I just popped them into some of the holes in the burner tube. I only filled every other hole in the corner. so that the flame still propagates around to the left side when lighting. I filled several more holes in the front row on either side of the corner bend to reduce the flame further. Since the nails simply slide into the holes up to the head, it is easy to experiment with fill patterns. And of course it is totally reversible.
It seems to work like a charm: significantly less flame in the corner, and relights even when turned down low and I blow out the flame on the left side. Again, I will elaborate and send pictures this weekend.
Don