Again... That adjustment is only at wide open throttle. There's a lot more to a fuel table than WOT.
Yeah, my dyno tune's A/F ratio is between 12.5 and 13.0 until the rpms hit about 4700 then the A/F is right at 13.0 all the way till redline.
When I was down at the shop last weekend I hung around after they were done with my car and "helped them" (yeah right) dyno a porsch that had twin turbos on it. He had a portable A/F meter on it and I saw it hit 15 on the ratio while it was idling and it is supposed to do that during idle and cruise like someone said. He was actually very rich though since they did a pull half way and I saw his meter hit 9.0 to 1. The A/F on the dyno said 10.0:1 so he was in the middle there somewhere. I left right after they starting working their way back up the A/F chart. That porsch was at 445 rwhp being that rich and only pulling up to about 4K. Strong little sucker!