I think the contract module is a mess because the OpenApi models aren't DTOs; they have builder logic, volatile properties, and lots of Jackson-specific assumptions built in. There is the reflectionless renderer, but it's not as feature complete. It definitely needs a revamp.
I keep meaning to look into it (and some sort of batteries-included framework), but you know... Baldur's Gate 3 happened, and Factorio's new expansion announcement has everyone excited to play the 400 hour long mod it's inspired by 😇.