I've been using that heat gun on IP film, as I have
alluded to before. Here's my first semi-scientific test on the technique. It's a 1500W heat gun on the "low" setting, and I hold the picture in my hand at about arm's length from the heat gun so I can feel how much heat the picture is feeling. I try to keep it around 100
oF, which is a temperature my hands kinda know because that's the temperature I keep my water bath to process C41
Anyways, the results! Pictures taken pretty much at the same time.
Ten minutes later. Picture on the left just developed on its own, picture on the right hit with the heat gun for said 10 minutes.
And here are the fully-developed pictures (scanned 2 days later):
Admittedly, to make it more scientific I'd have to take the exact same picture, same exposure, to see how the color balance is affected by the heat gun. I suspect that heat gun development increases the yellows a bit.