what we need the tool to do for our craft is to preview what the positive (unedited negative flipped) will look like.
I think part of the friction in this thread boils down to a tendency captured here: to regard one's own, personal preferences as universal. Evidently, they aren't. I personally do not need, require or want e.g. a view camera that puts the image upside up and shows it as black and white with a certain transfer curve. I'm perfectly fine with what the ground glass gives me. People who prefer to use a rangefinder camera (the type with an optical viewfinder) appear to be doing just fine without a WYSIWYG preview as well.
Furthermore, I expect it's highly likely that those who photograph on film are more likely to accept or even prefer a viewfinder that does show a facsimile of the final image as printed, projected etc. I believe there are two reasons for this:
1: Some (many) people who use film seem to embrace a degree of unpredictability and surprise when they get to see the images.
2: Some (other) people who use film appear to visualize the result they are aiming for mentally and arguably would be hindered or biased by a machine-made preview that does not interpret the scene on the basis of a human emotional response to it.
Both arguments result in the exact opposite of the requirement as you formulate it.
There will likely also be a considerable group who simply don't need the live preview, but wouldn't mind awfully if it were there, but they're on the whole not willing to pay e.g. $1500 for a brand new camera that has such a feature as they're perfectly happy with their $150 Canon AE1.
Overall, I think the vast majority of film photographers will experience your concept of an EVF-equipped film camera as antithetic or oxymoronic. While your arguments for an EVF as such make sense, the concept of your proposed camera does not hinge on just the presence of an EVF - as I understand it, it's still a camera that takes film. And that automatically means it targets a particular audience, which for the largest part does not appear to have any interest in such a concept. I'm not sure how you expect your reasoning to somehow change that. Do you expect everyone to suddenly go "ooooh, now
I understand, how could I've not seen this?"
Camera's with electronic viewfinders have been around for decades now. If there would have been merit to a Frankenstein concept that records on film but uses a digital display to approximate the final image, surely, companies would have invested in it. Fact of the matter is that the concept just doesn't make sense; it doesn't compute. People may like cars and they may like ice cream. That doesn't mean that a car with an ice cream cone for a steering wheel would be a viable proposition.