What do you mean redemption arc ?
How can someone like him be forgiven ?
I despise how the author see this. Vilain-to-lover is fine to a certain point. Dan has been raped and abused mentaly and physicaly.
Do you think him crying a bit and saying sorry is enough to make a make-up sex sweet ?
This sending a wrong message : no matter how toxic you partner is, as long as he is really sorry forgive him.
I really hope the season 2 is about making Dan gain confidence, love him self and finding money and love he deserve.
I would really enjoy him having a "redemption arc" where Dan may forgive him but not forget what he did ans refuse to be together with him for his mental health and self respect.
Edit : Face it, had JK been fat/old/bald/"ugly", most people would never want a redemption arc.