You know bud, your set up has plagued my woeful mind for more than a year now. Your video looks pretty damn good to me and most guys would be pleased as punch but I have a feeling you're a lot like me so what can we do here?
My first thought is that the "1/2 turn maximum" in the instructions is there because they have to set some sort of a guideline and that one works really well. One thing I learned from Barry Grant (not the man personally but dealing with his company) is to place much more emphasis on throttle plate position relative to transition slot (or enrichment hole in this case) exposure rather than a screw setting. With carbs, we're doing this stuff manually and not every threaded hole starts in the same position and you can't sit there with a lap top and increase the IAB by .2% at 700 rpm.
What's become an absolute doctrine for me is to get it to run the very best that you can, remove the carb and put your eyeballs on the enrichment hole exposure below the throttle plate and the screw settings be damned.
I had a wide-band and a vacuum gauge in the cab for 4 years and I can tell you that you have some wiggle room before the enrichment holes start flowing so try not to get too hung up on the half-turn deal but it's still a really good guide.
Another thing that's sure to spark (pun coming soon) some controversy is the CDI ignition. Regardless of the "engineering facts" that are thrown up around here, the only reason those boxes hit the plugs 5 times per cycle below 3,000 rpm is because they fire the charge horribly with a single shot. There's a place for those boxes and they shine in the right application but this ain't it.
I can't say that that's part of your problem or not but it's something to consider, although I doubt if it matters because you've already got the goods wired in
I wish my phone at the time had the audio that today's iPhones have because the sound is all jacked up but you can surely see the wine basically not moving. And that was before a decent ignition. http://jeepspace.jeepforum.com/video...1610#video1610
I guess to wrap up my ramblings, try not to get too fixated on a screw setting. Flip the carb over and if your enrichment hole exposure is in the green zone, life is good, even if you're at 3/4 in.
Plug gaps between .035 and .040 are a good thing, too.