We don't have to assume. The speed of causality applies to everything in the universe regardless of its properties.

I have a question about Quantum Entanglement.

If I understand things correctly, massless particles travel at the speed of light, and at the speed of light, within the frame of that particle, time is frozen.

If time is frozen within the frame of the particle from the moment it is.... created?.... then is this the explanation for why Quantum Entanglement works the way it does? The two particles are split but no time is passing for them so their orientation can't be set, but when we interact with the particle we interfere with it's frame causing time to begin moving within that frame which is what causes the system to collapse into it's final state? If the two particles had started life not moving at the speed of light would they have already collapsed?

Thanks, really appreciate all of you :)