You’re right. It’s Register Plus Redux, not core WordPress. So far, the only challenge is Twitter which does not pass back email, but I do not think I’m going to worry about that right now. There’s a fair amount of work to put another prompt in for email after Twitter connect and I’m not sure it’s worth it or the UX implications.
I’ll do a pull and submit some updates. I’m also looking at adding WooCommerce support as I need it and am unhappy with the other plug-ins. If I get it figured out, I’ll submit those in a different batch.