The core of special relativity is the relativity of simultaneity. In order to grasp how that works one can not escape the issue of the ontological status of events, especially space-like events. Mathematicians will not deal with that issue. With the advent of QM physicists became mathematicians. Most of them are solipsists/hard empirists/positivists etc, anything but realists. No wonder mathematics fundamentalists have highjacked the SR topics and forums. I think it is pointless to discuss the fundamentals of Special Relativity in such an environment.
Prove of this is that on this forum it seems acceptable to see SR, LET, etc as equal physical interpretations of Lorentz Transformations.
On a physicsforum SR thread discussions should stick to SR, Einstein/Minkowski, not Lorentz' LET or any other 'interpretation' such as bizarre philosophical QM approaches (what about observer created events?). In physics the mathematical SR spacetime diagrams refer to 'block universe'. But defending this is not allowed here. So I will not go into that.