I think we need to explore the body horror possibilities of hyperspace. Like, you know how it's bad for astronauts to be up in space for too long because of radiation and the effects of weightlessness on human physiology? What of hyperspace was like that, but *worse*. What if it had effects on your body, or even your mind, that are difficult even to imagine? What if if you spend too long out there, your body starts spreading out along the fourth dimension because there's nothing to hold it in place; and then when go back into normal space, you get 'flattened' back down into three dimensions but everything isn't quite where it's supposed to be? Or the matter displaced along the fourth dimension just clips out and whole chunks of your body just disappear? Or there's some exotic form of matter in hyperspace that, over time, replaces the normal matter in your body until you can't return at all because it can't exist in our spacetime? Open to other ideas.
