Isn't this paper more about simulation techniques than about reality itself? It looks like time reversibiliy (sub-planck length or otherwise) should be studied

Isn't this paper more about simulation techniques than about reality itself? It looks like time reversibiliy (sub-planck length or otherwise) should be studied in closed form or at least in non-lossy mathematical ways, not simulated with imprecise digital computers. Montecarlo simulation to calculate pi is just not a good way to know whether the digits of pi ever repeat or they don't.