Rethinking multi-grain timestamps

There's still no causality broken in QM with entanglement. You can observe some measurement of an entangled entity and know what result would occur if measured somewhere else at the same moment (and outside the light cone), but causality is not broken because to *use* the information, you must actually communicate with the other side (as you cannot influence the result without breaking entanglement; you're just learning things at the same time as elsewhere).
Note that the "interpretations" (e.g., Copenhagen, many worlds, etc.) are about *how* entangled particles do this.

QM doesn't have anything to say about black holes as it does not have a model for gravity at all. The problems are that black holes represent a situation where gravity is strong enough to matter (heh) on the QM scales.

And yes, there are gaps in the theories for what happens here. We don't know what it is.

PBS Space Time is a good source of information on these topics: https://www.youtube.com/c/pbsspacetime/videos