Each loader gets its own cache, but you can't actually have two loaders - you get failover OR... actually the only other loader we have is a test only loader or the fake loader for full graph analysis.  There's no longer a chain of loaders - you pick one.  Failover does reflection as a backup, but if you wanted a fully reflective loader, you would replace Failover loader with ReflectingLoader, or GWTFriendlyLoader (making that one up) or whatever.