Currently the only available metric is a total "Count" of items of the column. It would be useful if this metric is customizable - for eg, it could be a total of a particular field, say the [Order Intake] - then we would be able to see the "Sum" of this field right at the column top of the Kanban View Column.
This is similar to bringing the "Footer Bar" of Grid View to Kanban View, but bring it to the top instead!