Some developments ...
It seems with the cooler weather my car has tended to want to stall out more when coming to idle while stopping - I'm not sure if there's any relation to the weather or if my car is "re-learning" itself some bad manners since my tune.
Note that I also have a Dakota Digital GPS sensor feeding my VSS and my tuner spent some time working on idle quality. The DD GPS didn't do much for me but the tune made a noticeable difference. More recently it's shifted back to behaving more like it did pre-tune.
One of the things my tuner noted while I was at his shop was that he thought my MAF sensor was too close to the air filter. I have the sensor located the mandated 10" away from the throttle body and I'm using the typical 4" inlet pipe most LS motored guys are using. This places the MAF sensor about 6" or so to the air filter.
So I pulled out the angle grinder and cut my tube to bits and re-located the MAF sensor to about 6" from the throttle body. The sensor is now almost even with the forward cross-bar of the engine brace.
I took it out for a spin and it seemed like an immediate fix - slowing down to a stop, the RPM would drop down a bit and catch itself within 1 "swing". When things were bad it would surge back and forth until the engine died unless I gave it throttle. After the initial tune it would hunt/surge maybe once every 20 stops or so. Lately it's been more like once every 3 to 4 stops.
Unfortunately I didn't get to drive the car too long as the car sputtered and fell silent.
I was pretty lucky that my father-in-law was still in town (he was due to leave the next afternoon) and he was able to bring the trailer out and give me a hand. This is the first time I've been left on the side of the road, thankfully I was close to home. I was getting ready to do a ~200 mile road trip this weekend!
It happened at a pretty busy corner and I was able to get a hand pushing the car off into a side street without much difficulty. Rush hour wasn't the best time to have a breakdown!
I got to test out my tow hook - it worked like a charm!
Some video evidence of my mis-adventures! Here's a YouTube link: