No clobber here, Glauber (hey it rhymed!) 
Isn’t it all conjecture anyway… ?
Speaking of, the fellow who repairs my flutes just told me last week or so that moving the cork really doesn’t improve anything – I’d always pushed my Boehm corks in toward the embouchure hole a bit to improve the low register; it was the wisdom at the time I learned it, I guess. Although I SWEAR it made the lower notes easier to sound … ! So I’m still not convinced, but his explanation of absolute vs. relative tuning did make some sense.
Anyway, from there I guess I just figured out the best way for me to play in tune, much as Glauber suggests Galway does. (Interestingly, in my experience, spinning vibrato really fast like he does can also sharpen you up, but who wants to do that? 
) … but regardless, I think we all agree that you HAVE to learn to play the flute in tune. In other words, play the cards you’re dealt. Most flutes seem to have at least one funky note, especially these Irish guys. And that funky note can change as you change the tone quality – i.e., my E tends to be sharp when I’m really bearing down – altho’ I don’t know why – but my D goes flat when I don’t.
So I follow the time-honored tradition of “lipping,” i.e. constantly making tiny adjustments with my lip to my tuning & tone, same as I’ve always done on my Boehm.
Incidentally, the octave-D-test works fine on my conical-bore Hammy. Although G has a point: I don’t know if it’s supposed to be used as anything but an indicator; i.e., to let you know your middle D is high compared to your low D so therefore you need to lip down … it isn’t a matter of moving the cork, necessarily, but of moving your lip, jaw, chin, rolling out, opening your throat, or whatever works to compensate.
Hmmm. Does this pretty much take us back to where we started: figure out where the flute’s out of tune, and then figure out how to play it in tune?
) flute. Maybe with the simple system flutes the differences between individual playing styles matter more; the Boehm flute is so well vented that it tends to make all notes equal.