Extending redirectToIDP Method on Sign-in Widget

We are extending the sign-in widget, and fronting a variety of external IDP providers. The issue below describes the behavior we are looking for.

it seems that there is no way to forward to our request context with Tokens, we are currently using the idp.requestContext to redirect the user to the SP initiated login after the IDP auth flow in order to sign them into the application. However, it is not sufficient as we cannot pass items like relay state (which the requestContext was meant to be used for) Any suggestions how to implement the flow in the ticket while still being able to pass things like RelayState.