1. You can not see traffic directly into sun - well not unless you are wearing an arc welding helmet.
2. Dazzle caused by the sun reduces the ability to see traffic removed from the glare ball.
3. I have flown for the RAF and three world majors. In all of these it was common and accepted practice to place a map or other obstruction over the window in line with the sun. You ain't goin' to see anything there anyway.
p.s. It is, of course, up to the ol' man whether you use this technique or not
