You may (or may not!) be conflating summary statistics with signal filtering here. For latencies as experienced by interactive users, the tail of the distributi

You may (or may not!) be conflating summary statistics with signal filtering here. For latencies as experienced by interactive users, the tail of the distribution (very high percentiles including maximum) are the summary statistics that matter, period. It sounds like in your case the data is a mixed distribution of both non-actionable garbage and actionable signals, and if you could filter out the actionable, you would benefit from looking at the tail of that distribution. However, the best way you have of filtering out the garbage currently is to filter out the central portion of the mixed distribution. This comes with some false negatives and false positives, and may (or may not!) be the ideal filter in your case. It would be interesting to try to find out!