There are many styles of film even from one company. Each has different properties and different abilities. You get what you pay for. It costs a little more money to make better film, but the result is consistently better results. Always choose the best film possible because the film is what is brought to the screen-exposure device. Don’t forget, we are “screen” printers. If your screens are second rate then your prints will be too. There is just no other way to put it.
The emulsion layer on the film certainly helps speed the drying process and keep edge quality high reducing dot gain. Avoid using films with a thin, almost “clear” appearance and never use a “non water proof” film. Dye ink (recommended over Pigment) is water based so use a proper film. The name alone “non waterproof” should tip you off that it’s not the best product for your needs. The slightly cloudy emulsion of the film does not affect the exposure process but it grabs a hold of the ink sprayed onto the film during output.