Show delta to reference in scatter plot

Currently in order to show differences compared to a reference in a scatter plot the reference needs to be calculated by the user, either as a calculated column or in the scatter plot itself. A scatter plot has all the information already available, with the only action required is to subtract one series from another. Being able to do this natively from the plot would be a lot more convenient than having to reproduce the aggregates which make up the series readily available in the visualisation.

Attached a screenshot of an example where in the top plot the aggregates are shown while in the bottom chart we can see the deltas between the blue and red series.