Generate async counterparts in an inherited type

[maca88]

interface IInterface
{
   void SomeMethod();
}

/*
methodConversions:
  - conversion: ToAsync
    containingTypeName: IAsyncInterface
*/
interface IAsyncInterface : IInterface
{
}

The desired behavior is that the async counterparts from the IInterface would be generated in the IAsyncInterface interface. Originally requested here.