Does anyone have a suggestion for editing black and white film digitally? What I have an issue with is that film grain doesn't really produce the gradients that digital does, and adjusting the levels attacks the whole picture. What it really needs to do is average a larger radius before it considers a section a midtone. For example, in a white sky, there are still granules that are midtones. But when you are trying to darken the midtones, you are not looking to adjust the sky, you are just trying to target the main subject. The same thing happens with the contrast controls to some extent. The contrast increases at the micro level but not the macro level, making things look blotchy.
What are you using for an editor? If you are using PS, I assume you could use layers to isolate edits to certain areas of the image. (I have no experience with PS, just guessing here.) If you use lightroom, you can use gradients and brushes to isolate areas of the image. (LR I have experience with.)
I scan mine using an Epson V550 then edit scratches with Lightroom CC. You could see a sample below. This was taken under fluorescent lighting and the tonal range seems ok. I would check your scanner setup.