It seems to me the ultimate nature of reality is outside of space and time. Why then haven't we tried to use a different type of mathematics or model that doesn't have anything to do with distance. Obviously this type or math would work for anything that has to do with causality and what we observe in the physical universe but to answer what causes it would require a different type of math. There has to be theories and ideas based on this that other physicists have derived as well.

Essentially if your entire model is based on spacetime down to the mathematics that you use, then it will be impossible to explain what the nature of spacetime is based on those models.