Am I right in my (very limited) understanding that they derive their 'observables' (i.e. indicators that would prove we are inside a simulation) from the assump

Am I right in my (very limited) understanding that they derive their 'observables' (i.e. indicators that would prove we are inside a simulation) from the assumption that the space-time continuum is discretized in a certain way? By the time we are actually able to perform a simulation on such a scale would the numerical method not have evolved as well and possibly produce totally different kinds of 'observables'? I realise I am totally out of my depth here :).