There's no objection, but I think this solves a different problem than above described, and is possibly a more complicate matter in itself than it may look like. First, are you describing a way to typecheck macro so that it doesn't generate ill-typed code? The type system that does this is active research (I think requires modal typing?). Also this does not increase the expressive power of untyped Lisp macro -- just making them safer, while I was proposing their expressive power is unsatisfactory and should be enhanced via a sort of reflection. That would only makes them even harder to type!