Interesting, conceptually. It could be argued that "documentary" work depends on a degree of technical transparency, i.e. the tools used don't impose an undue amount of influence on the image. One traditionally doesn't shoot documentary work with a fisheye, for example (I personally restrict my approach to using lenses between 28 and 75mm to avoid undue perspective distortion, when doing "documentary" work). These parameters are arbitrary, and words like "documentary" beg for definition, of course. I'm interested in how you think about using polaroid materials for documentary work, as they have such a strong and unique signature.
This is clearly a question posed by someone with to much Art School under his belt, but your educational background is similar to mine, in that regard. Just thought it might be an interesting can of worms to open...