SocArXiv accepts law papers, as we always have. Some of the bells and whistles he wants we don't have- like ranking and email subscriptions, but those can be built using SocArXiv. We don't have funds or staff to help build that, but law schools do.
SocArXiv
not sure if everyone can access this, but I just learned about some dramatic changes to SSRN from Steve Bainbridge's Substack. This is really bad; SSRN has been how I keep up with scholarship in my field from a variety of researchers
www.stephenbainbridge.com/p/the-social...
Significant and unwelcome changes to what had been legal academia's major open source scholarly repository and notice system