I got a backer (150$: 10 sheets plus a 5x7 print as a keepsake) after my submission for the 'SALT' MSA, performed with my 545i holder and T-54 film:
What I find attractive in particular is their claim that you can use the same parameters for correct exposure of positive and negative. I expect that one can at least learn to judge the negative correctly by the positive.
Then you know that you have 'got the image' even your motive is not completely immobile - and paste it together with the (hopefully few) other exposures in your logbook and add some notes. The final image will then be the print of the negative. This would be a great tool for learning and improving! And so it would be really a new development in analog photography - which would have been highly admired even before digital photography (almost... :-) killed polaroid.