Here’s a link to an interesting article about the bastardy of Edward V, and the reception of Richard’s claims concerning it. Specifically with regard to the IPM of Hastings. You can download the full PDF.
And as a ‘taster’:- “….Richard’s claim that Edward V was a bastard did have traction in the localities after the passing of Titulus Regis in January 1484….”
Not that the entire article is pro-Richard.