I'm FBO and I don't have a sound like that... not xi though, and I have exhaust. But that whine was easily reproducible is 3 of your runs. I'm stumped. It pulls fine, psi looks good. hmmm...
edit: I've suffered several boost leaks in the past, and NEVER have I heard a whine like that. It almost sounds like an impeller or oscillation under stress. definitely rotary, not wind, not boost leak. just my .02