From what I can tell it seems as if all of your conclusions are based on your experience using this tweeter in a non-horn app. The meat of my OP was to figure out if comparing the same driver in a horn vs. non-horn app is a valid comparison or if certain parameters change when a horn is added (and if so what and to what degree w/ a 90 degree 3” wide horn in this case). I do know that FR is extended on the low end (you can see that in the graph). The impedance is also affected (which is an indication of lower Fs). The only real factors left are excursion and distortion from what I can gather. If the “magic” of horns keeps all of those in check then it looks like we could have a practical option for the tweeter line (or the start of one at least if this needs to be hashed out further).
I knew from the outset that this would be horn discussion more so than one centered on LA’s and I debated whether or not to even ask it on this forum. With the cost of building a low compromise tweeter line being one of the most of discouraging factors of building a LA I wanted to make sure the topic got referenced where others w/ similar apps could see it. Furthermore, I know Wayne is pretty knowledgeable about horns and he would probably be helpful no matter where the discussion took place.

Later,
Aaron

As to horn loading, I don't know the c-to-c answer. Have you read Zaph's hornl.oading of a dome tweeter?

http://www.zaphaudio.com/hornconversion.html