Heaven and hell seem to be outside our spacetime, usually. From God's view, it must all be different. Like the geometric fantasy, Flatland, where a three dimensional body passing through the two dimensional Flatland can only be perceived by the Flatlander as moving points, but the three dimensional body only sees a line. How could a complex future be shown to a mortal so that it could be completely grasped? Look at the last chapter of Daniel. He ends up overwhelmed and the messenger speaking to him basically says don't worry, trust that it will be all right. So yes, many visions could be allegories or other versions of the true meaning. But all we have to go on is what was said, that we can compare to our experience.