I would like to hear about what you expect to put into your fat carbons to make them perform the best.
I have been messing with some brand X fat shafts and the more I work with them, the less I'm impressed. I found them very sensitive to nock tuning- meaning some would be way off in POI after the build (2" @ 20 yards)....the worst I've ever seen. But, nock tuning would bring them together. After nock tuning, I tear the same hole consecutively shot-after-shot through paper with a given shaft. Change to the next shaft and it will have it's own unique but consistent/repeatable tear. Like I said, POI's are good after nock adjustment but paper tuning is not- I can't get satisfied with my tuning because I can't establish a trend across the group of shafts and they are unique enough that tuning (bow adjustments) to one would be counterproductive with others.
I've only seen this once before and it was in a set of VAP's that found their way back to the dealer who also couldn't get them to shoot- even in a hooter shooter. Have you paper tuned with multiple shafts out of your dozens?