This is the wrong behaviour, I think - it looks like it will just break Homestead without a HSS. When we don't have a HSS, we should preserve the existing behaviour - which I think means basically the type parameter, always returning the cached data, and *never* deleting data.

(This is because without a HSS, we don't keep track of registration state outside of Sprout, so don't need special treatment of deregistrations/re-registrations/etc.)