What an idea! I don't think it would be great for LF, it would scratch too easily, but on a Bronica or Hasselblad it would make for good shooting with the Maco films. I'd probably try to get the polyester filter, harder to scratch than the gelatin. Biggest concern is how rough the light seal would be on the filter as it is inserted into the slot and whether there would be any light piping through the edge of the filter.