I think there would be three main benefits of using Negative Lab Pro in a primarily black and white film workflow:
Time Saving - rather than having to manually invert and correct each image, you can do that in batch with Negative Lab Pro. You can convert hundreds, or even thousands, of black and white images at once if you’d like.
Workflow - all the edits in Negative Lab Pro happen non-destructively against the original file, so no detail is ever lost. You can edit the same image multiple ways if you’d like (using virtual copies) without the need to create additional images. Or go back and tweak images where you left off without worrying about clipping any information.
Accuracy, Control & Image Quality - Using Negative Lab Pro gives you much better control over the accuracy of the tones in your black and white conversions. For starters, it uses a special camera profile that keeps the original information linear. I then recommend using the “linear + gamma” tone profile, which is truer to correcting for the gamma of black and white film (as paper would). You can fine tune the tonality of your image to the smallest degrees without ever touching a tone curve directly.
A few examples of Negative Lab Pro with black and white:
Of course, I’d also highly recommend you play around with the free trial download to see what you think!
Creator of Negative Lab Pro