I’m surprised continued state supervision hasn’t been challenged in your state yet. Probation and parole are recognized as punishments. If you have served your adjudged sentence, then you are being punished “ex post facto” which is roughly translated to “after the fact” and it is strictly prohibited in the constitution. Ex post facto cases make up the bulk of challenges by registered citizens; however, the courts are able to step around this by labeling registration as a civil measure and non-punitive. There is no way they can label probation and parole the same way. I would suggest contacting a legal clinic or the ACLU in your area.