6 day competitions still have loads of people riding 808s
6-Days isn't racing, it's a circus with billboards. Wheel choice isn't determined by what's fast, it's determined by what the rider is being paid to ride. Marginal gains don't matter when the result is decided before the riding starts.
Who is using 808s on the track? Comete/Io or GTFO at the top level.
Also, track racing isn't zero yaw :-)