From what i understand alternative processes generally require a pretty clear, well defined, high contrast negative to start with. Am I mistaken?
Most alt processes have a high exposure range. It is not uncommon, for example to see as many as 7-8 stops of exposure between paper-white and maximum black. That means you need very dense negatives to get a full scale print (i.e. one with all the tones between paper-white and maximum black). That's what people mean when they say alt processes require high contrast negatives. It doesn't matter if you use film or digital negatives, you just need to calibrate your process to achieve this. This is easy with film, more difficult with digital negatives.
The content of your print whether full range, high key or low key is a different thing. I make platinum/palladium prints, and have successfully made full range prints, very high key prints (so high key that the image disappears when you try to take a picture of the print), and very low key prints.
In short:
1. Calibrate your process so that you can achieve a full range print
2. Make pictures that are aesthetically pleasing to you by using that calibrated process
3. Enjoy the wonderful world of alt printing