No idea. I went through your tune again and compared to mine which I have reved over 7k (my limter is set to 7100). The only other trouble shooting steps I can think of require more control over the ecu than I think we have. Can you log the actual crank and cam sensor inputs? Like the waveform they produce? The only thing I've seen do this before is interference in the cam/crank signal that develops at certain rpms either from wiring, insufficient filtering in the ecu, a marginal sensor, sensor being the wrong distance from the ring, or just getting more pulses from the trigger than the ecu can handle/time.
Unless your spark is marginal. I've had other cars that had spark break up in boost and the ecu didnt detect it as a misfire.
Besides that... I dont think I have any more ideas. Maybe a video would spur someone with this.