I see Manifold as a huge leap past previous tools Immutables or Lombok. I understand there's a use case where you want to add these language features to an existing code base. But for the most part if you want the language features on the JVM, you should probably just use Scala. That gives you a set of established patterns, best practices, libraries, and a community of users.

If you want type safe SQL in particular, you can pry JOOQ out of my cold dead hands.