Perhaps a simple question that you could answer.
Suppose that we assumed that gravity has a quantuim limit to how far it can act? So if we visuaized it as tendrils emanating outward, those tendrils have a fixed length. While an acxcellerating object is within that length, it is retarded. Once it escapes, it accelerates again.
I'm sure someone thought of this and rejected it. Can you explain why?