The original commit (502f355a65456ec50d7bea29ac5f1f92a9a547bb) that introduced those case classes said it's just a convenience. I don't really understand why convenience methods related to incremental compiler do not live in a subproject related to incremental compiler.

For that reason, I think we should not add more code there and just grow what's in incremental compiler so other projects like zinc and Scala IDE can benefit from the same API.