If that's your definition, then it's an empirical question whether a given model is an interpretation, because it's often contingent and difficult-to-demonstrate that a given ontology is necessarily 'invisible', as opposed to 'potentially-testable-but-as-yet-untested'. Impossibility proofs about future scientific experiments are no easy task. So we can only speculate about whether Many Worlds, Bohmian Mechanics, Collapse theories, etc. are 'interpretations' in your sense.

(And by 'invisible' I gather you mean 'empirically equivalent to a certain set of rivals' -- so whether something's an interpretation is always relative to other models, the real predicate is interpretation-compared-to-x.)