Provide or change the current default value of Aggregation from 'Max' to 'None', so that user can select his desired aggregation from UI.
Thanks for the suggestion. Your current workaround, if applicable, might be to assign a function to the series > aggregate attribute (http://docs.telerik.com/kendo-ui/api/javascript/dataviz/ui/chart#configuration-series.aggregate) which returns data based on your custom logic.