Ah the good old days when Polaroid type 55 (or any type) was affordable and available. Checking exposures and checking focus and checking composition, there was no learning tool like Polaroid. I used to always shoot a polaroid no matter where or what. I even had a 4x5 back for my 8x10 especially for shooting polaroids. Of course that won't help with loading backwards and bad processing.
the best tray for processing 4x5 film is a Pyrex glass bread loaf pan. Forget the tacos and burritos.
Dennis