The reason proper tiller is important for noise reduction is that improperly tillered limbs will return to the braced position at slightly different times, setting up a vibration. For many years, BW recommended a positive tiller for 3 under that was higher than any of the other brands I know of, all of which recommended either zero tiller or slightly positive. I wondered about that, and there were debates on the BW forum about whether BW's recommendations for 3 under tiller were correct or not. It is interesting that they now recommend zero tiller, which is consistent with the other brands I am familiar with.
I know that Rod Jenkins ordered a bow from BW several years ago, and specifically requested zero tiller, even though that wasn't BW's practice at the time. When he shot the bow in a class I attended, it was one of the quietest bows I've ever heard.
I don't know that it would be worth it to pay BW to change the tiller, as my understanding is that it won't really affect the accuracy of the bow. OTOH, if you wish you had ordered a bow that was a few pounds lighter, you could kill two birds with one stone and in that case, it might be worth it.