Sorry, but that won’t work – we calibrate the machines to fixed film stocks and standardised chemistry.
Everything is consistent and repeatable, it isn’t much like playing around with a film camera and a processing tank to see what happens. The idea is that the negatives we produce will print in the darkroom pretty much as you have created the image on screen, not to introduce unpredictability.
In other words, the creativity is done with the digital image and what we produce is merely an intermediary between the computer screen and the darkroom print.