Ok, let's keep the topics clear on here. This boils down to a few different issues, let's handle them one at a time.

1) You claim there is an odor in the cabin (coming through the vents).
2) Other people have complained and GM says it's from the PTU vapors, issued TSB to change charcoal filter.
3) Filter change didn't remedy the problem for you.
4) You're now looking for other answers and fixes, etc.

Ok, so my first question is are you the first owner, or did you purchase used? Also, are you the only one(s) who can smell it, or does everyone who gets into the Traverse (and I drove Traverses on/off for a year or two, they're pretty sweet vehicles) smell it and get sick to their stomach? Since you've documented this out so well I also assume that this is a first-time occurance for you with getting a bad smell in a car like this? I'd like to see the TSB to see how many people are complaining about this, maybe it's something that builds up over time.

Thoughts: Can you try to mask the smell with something like an air freshener or ion-based air purifier, or is it beyond that? Those things can do wonders, and just because it might work doesn't mean that you have to do it. It's just a suggestion to help you otherwise enjoy what in my opinion is the best full-size crossover platform on the market today in it's price range.

Other Thoughts: If this was a big enough issue, then GM will come up with a fix. Just because they don't have a "fix" now, doesn't mean that they won't have a solution in the future that will alleviate your concern on this.

Also, not to get too personal (and more for the sake of my personal curiosity), but do you have a sensitive sense of smell anyhow? I know that doesn't really matter, my wife could be a substitute bloodhound I think and she smells things all the time that I can't smell at all.