This is the key to understand reality: Speed of light means instantaneity at the same time.
As you correctly state, this solves the problem of entanglement, and from there, all quantum conundrums can get solved. Take a look to my article, where from this simple premise I can make sense of all quantum weirdness:
I'm also writting another article where from this fact (that all the lightlike interactions that compose our universe each time unfold instantly, each one linking two spacetime coordinates, no matter how distant in space or how old in time) I show (through more than 40 spacetime diagrams) that all the concepts we use to understand physical existence (our subjective frames of reference and spacetime units) come from the relationships among the lightlike interactions we can detect.
Every property, entity or phenomenon emerges from these instant (but lightlike) interactions. Every structure or entity, every sequence or process. They define the resilience, awareness and agency of anything physically existing in the universe.
Lightlike interactions shape reality each time.
