It doesn't require that. You can do a strangler pattern of sorts and use task for the interop layer, then run each call site through a small helper that convert

It doesn't require that. You can do a strangler pattern of sorts and use task for the interop layer, then run each call site through a small helper that converts to F# async. Or, hell, just throw caution to the wind and text replace. I've heard some folks do that and it worked out well for them + wasn't much time to clean up either. They're especially happy to have better stack traces too.