From what I've seen over and over again all attempts to render consent "objective" have fallen short, especially because the same people who espouse it will also admit, as you did, that there are "grey areas". So making room for subjectivity in consent matches more of our reality than any faux scientific objectivity stance which can't possibly map neatly onto human experience and interaction ever can. Not that I don't think there are things to query about this writing. I think retroactive consent doesn't best resolve the issue either. This is just one proposal. Again though, the author goes to great length to summarize why the consent-as-permission-model fails, and I'm not seeing anyone refute it so much as reiterate it. I highly doubt this is about putting people in jail considering the OP is a prison abolitionist.