Hi Greg,
As discussed elsewhere, I don't know what you need to do to convince your camera drivers to include the overscan region in the images you download (my Apogee U16M has a Digitize Overscan check box in the Maxim set up dialog and that's what I use) but once you have appropriate subs and calibration frames it is easy to process them in PI with the BatchPreprocessing script. Just set up appropriate overscan parameters in the Bias tab and that's it.
I first started playing with this when I noticed significant variation between the average value of my bias frames. I have demonstrated, to my personal satisfaction at least, that the quality of my integrations is measurably better when I use overscan calibration and I now do it as a matter of course.
Cheers,
Rick.