Then what time governs the propagation of light? If there was no such one, then it wouldn't have a speed.
This may be where you are confusing the issue – time does not govern anything, especially the propagation of light. Time exists as a mathematical quantity and is not some physical quantity in terms that anything depends on it. There is nothing in the physical universe that depends on time.
And you can't say that time stops at the speed of light, because that's just a corollary of the presupposition that events can only propagate at the speed of light - that doesn't explain how light propagates.
You don’t need time to explain how light propagates.
Since the speed of light is still an absolute limit in GR and it is always the same (in the same medium) there is by definition a CONSTANT speed at which it propagates
Yes.
out of which falls the propagation of events.
No, you are asserting that the speed of light is determined by events and/or determines those events– it does not.
So, some frame-independent time defines the propagation of light, and the propagation of light governs the frame-dependent propagation of events. Time need not be absolute, but the travel of the photons is still governed by a non-frame-dependent time.
Again no, the propagation of light is exclusively determined by the permittivity and permeability of space. Time is not needed to explain this.
This may be where you are confusing the issue – time does not govern anything, especially the propagation of light. Time exists as a mathematical quantity and is not some physical quantity in terms that anything depends on it. There is nothing in the physical universe that depends on time.
And you can't say that time stops at the speed of light, because that's just a corollary of the presupposition that events can only propagate at the speed of light - that doesn't explain how light propagates.
You don’t need time to explain how light propagates.
Since the speed of light is still an absolute limit in GR and it is always the same (in the same medium) there is by definition a CONSTANT speed at which it propagates
Yes.
out of which falls the propagation of events.
No, you are asserting that the speed of light is determined by events and/or determines those events– it does not.
So, some frame-independent time defines the propagation of light, and the propagation of light governs the frame-dependent propagation of events. Time need not be absolute, but the travel of the photons is still governed by a non-frame-dependent time.
Again no, the propagation of light is exclusively determined by the permittivity and permeability of space. Time is not needed to explain this.