I'm looking for a way that I can get Simple Injector to locate services registered with the Xamarin Forms Dependency Service, when the services cannot otherwise be resolved by the Container. Is there a way to do this with Simple Injector?
Unregistered type resolution can be implemented using the Container.ResolveUnregisteredType event.
Do note however that you should take my warnings as stated in the comments very seriously. Your scenario is not a good case for unregistered type resolution.