support for polymorphic recursion

Since rigid type variables have been introduced in inferno, I would like to know whether it is already possible to support type annotations for polymorphic recursion. I know type inference for polymorphic recursion is undecidable, but I am referring to the solution already provided in OCaml, i.e., by explicitly annotating polymorphic recursive functions with their type schemes. Is it possible to implement this using the current API already? Is it planned?