That's a major fallacy on this board: the assumption that two synthetic coatings will cross link. Truth is, the terms "synthetic" or "polymer" are so vague that it opens the door to many many many different types, and not all types cross-link the same.
I would have to assume that Blackfire and NXT share very little, if anything at all, besides a very very general basic formulation. Given that assumption, it's hard to believe that there could be a huge compatability between the two. This is not to say that applying one over the other makes the one on top disappear. It's there, but how durable? Is it any more durable than putting blackfire or NXT over a carnauba? Over regular, clean, polished paint?
This is also why I don't understand people who say "AIO leaves a good acrylic for the [blank] to bond to." It's probably has more to do with AIO's cleaning ability than the acrylic, since it's a stretch to say that every synthetic sealant can buddy buddy to an acylic, or to every other synthetic on the market.
There is no dry-detailing method to this. You either put both onto the car and see how it holds up, and come back and say it does and it becomes the next thing to do, or it doesn't work and you're left with a surface that's no more protected than it is now after a few weeks.
