You either don't get it or you are trolling. Einstein's elevator metaphor did not at all draw any important bits from the impossible construction. A spaceship

You either don't get it or you are trolling. Einstein's elevator metaphor did not at all draw any important bits from the impossible construction. A spaceship under constant acceleration works just as well. A thought experiment that creates a problem out of an impossible premise is just worthless as such. First of all, everything can follow out of a wrong premise, and secondly you can create an arbitrary amount of such experiments, preventing any insights.