Granted, and it's not exactly dangerously lean (far from it), but given that there's already a slight blip in the power graph at that point anyway I'd have expected the AFR to follow the downward line as boost increases, not go back up briefly from where it was at 2.5K. The car is still under boost between those points (3psi - 5psi) too.
I'm no mapping expert at all and I'm not saying for one second that it's a bad tune (far from it, I'd be very happy with that!), I'm just trying to expand my knowledge at these things should I go down the same path in the future. Sorry if it came across as a harsh criticism, I certainly didn't mean for it to.