I was thinking of something like a 6 X 6 folder, with perhaps the sensor on a foldaway screen in front of the film (automatic focus adjustment when switching to film mode) and one you could programme for the type of film/look you had in the camera like fujichrome or Tri-X. All shots taken in digital mode assessed on the back of the camera and then if you really like what you get you take one on film (doesn’t help with decisive moments if not repeatable), but would ensure a great set of film images and all your best shots with physical integrity.