The current definition of Self allows for actions of any type to be dispatched in some cases, what may cause runtime errors:

type Self props state action = { props :: props , state :: state , instance_ :: ReactComponentInstance }

This happens because action does not exist in the body of Self. A possible solution is to either newtype it (breaking change), or change it to:

type Self props state action = { props :: props , state :: state , instance_ :: ReactComponentInstance , action :: Proxy action }