What I'm trying to convey is that the statement "entanglement is instant" is implementation dependent. You can meet the specifications of quantum mechanics usin

What I'm trying to convey is that the statement "entanglement is instant" is implementation dependent. You can meet the specifications of quantum mechanics using a simulator where entanglement is instantaneous, but you can also meet those specifications using a simulator where entanglement is not instantaneous or where that concept doesn't even type check. What we can objectively say is that entanglement doesn't care about the distinction between time-like separation and space-like separation. If two non-communicating parties are entangled and they perform an experiment, there is no observable distinction between the cases where one of them goes first or the other goes first or in whether there is time for light to travel between them in the delay between their two parts. But that is much looser than requiring the effect to be instantaneous in some unspecified frame, because only requiring that there's no observable distinction is a much looser constraint than specifying that it must be instantaneous. And the only thing that we can experimentally verify is the looser constraint.