I think Bullseye would be interesting to see, because he really would challenge Daredevil and Karen's idealism. I don't think Daredevil's "there is good in everyone" speech applies to Bullseye. I feel like comic book DD would not see any good in Bullseye at this point, Netflix DD is a bit younger and more idealistic. I don't think Nelson and Murdock would ever defend Bullseye for example, Punisher's motives are understandable on some level, though not defensible. Bullseye's motives are not understandable or defensible
I think they would have to work hard to make Bullseye as monstrous as Kilgrave, but it could be done, Punisher litters the streets with dead criminal, Bullseye litters the streets with innocent people, some he is hired to take out, others that he killed for fun. He would turn Hell's Kitchen into a nightmare, where he would declare open hunting season on everyone and far more innocent blood would be spilled in Hell's Kitchen.