Great usage / application! I'm using it to both understand legal documents and to create a law firm's new client ingestion assistant. Potential clients can describe their legal situation in any language, which gets converted into the language of the attorney, with legal notations of prior cases.
I'd be interested to hear how well it works. In my experience, GPT is good at common legal issues, but pretty bad with nuance or unusual situations. And it can hallucinate precedent.
It requires quite a bit of role framing, as well as having it walk it's own steps in a verifying pass. But for an assistant helping a new/junior attorney it is quite unnervingly helpful.