I've heard nothing. Kilgore has responded to this before, but it was over a year ago. Maybe you can ask him directly, but the best way is via Discord chat. And be patient for him to reply. I hope he will build a Season 4 SDK for us - not having it does not prevent us from doing dev work on the side, but having it would be a heck of a lot better, so our new content interfaces optimally with existing content.