We have reformulated White's MSER to provide a spectrum of truncation point selection heuristics which differ in their treatment of autocorrelation. These include a method effectively equivalent to Chodera's maximum effective sample size heuristic. We tested these methods by generating ensembles of synthetic time series modelled on free energy change estimates from long absolute binding free energy calculations. Heuristics were assessed by their RMSE to the infinite-time ensemble average of the synthetic data.