I can see there are methods for finding a PlayFab Id from a Platform Id but there doesn't seem to be a way to get the Platform Id from the PlayFab Id.
When doing cross play we can't share the Platform Id across platforms so players must be identifiable via their PlayFab Id, however when we need to get the players avatar on (for example) Steam we need to turn that PlayFab Id into a Steam Id.
What is the suggested method for doing so?