Sorry to leave you hanging. The short answer is no. This has been partially due to bad weather on the weekends (why does it have to rain/snow/flood on my 3 days off each week?), And partially because I've been lazy.
I did pull the IAC hoping to spot something, but there were no apparent drag marks and everything is still shiney clean in there.
I had an OH SHHHI... moment a couple days after posting this that might offer some insight to someone. Someone pulled onto the highway In front of me while running about 70 mph (2300 rpms in 5th) and my trucking instincts kicked in. While on the brakes hard I jumped from 5th to 3rd for the compression braking. Rpms jumped to about 3800, not sure of ground speed at that point... I'll have to check that (pardon the large attention sp- oh look, shiney. Lol)
Once my nerves settled down I realized that the idle was behaving like it should. Smooth drop to 750 from anywhere in the rpm range, with any throttle position. This lasted for about an hour. Unfortunately I haven't been able to duplicate the results, so it might have just been a fluke. Only thing I can figure is the sudden high vacuum caused something to seat temporarily, but I'm still not sure what or where.