Currently the 'Summary' function for a grouped value table is predetermined by the aggregate function for each feature. For example, any feature aggregated by 'Count' is summarized with a sum function (the sum of all grouped counts). It would be useful to summarize an aggregated feature by a choice of functions. For example, to summarize a feature aggregated by 'Count' with an average function (the average of all grouped counts). Hope this makes sense, thanks!