Calculation of median among a set of values probably should be event based and not time based. While TagAvg historical has been time based, it has been enhanced to be optionally event based. There exist a Median() function to calculate event based median.
If I have misunderstood this idea, please provide further clarification.
TagMedian would be very interesting. It could be like TagMean but getting de median value between these timestamps based on events (by making this option available in analysis, summaries, RTQP, Event Frames templates...).