Yeah Bob Axsom did a lot of that testing. I have downloaded and archived many of his posts.
Tom, one thing with pressure in the cowl, it leaks all around the perimeter, and I noted in one post (forgot which one) that leakage from the gear exits blew off the transition farings. There are lots of places for these "jets" to disturb flow. I'm sure you know this looking at your FWF pictures, but did not see how you addressed this aspect. You probably already covered it.