I found a gentleman on an ARX page on FB and he is getting close to producing these parts. Acr stock adapter, rail extension, and a lower that accepts AR style grips. Personally, I'm very excited to know some cares enough about the platform to help innovate aftermarket parts. This specific individual used to work for another company designing parts for firearms, so I feel like he is competent enough to successfully pull this off.
He is making a lower without the cut outs in it.
He is making a lower without the cut outs in it.