Proposal:

HSQuery createHSQuery(SearchIntegrator integrator, IndexedTypeSet targetedTypes, Set<CustomTypeMetadata> customOverrides);

We could then either have two methods, one of which omits the customOverrides , or simply expect people to pass an explicit empty set.

Not sure if it's worth it, but considering that IndexedTypeSet allows me to implement several optimisations, maybe there's some benefit in introducing an TypeMetadataSet ? Just an idea to explore, I wouldn't want to over do it with these custom types.