Fact column subtotals in data view

The recent addition of filtering and sorting in data view is fantastic. This feature will be very useful to those developing data sets. What would help developers even more, particularly those adding calculations to their data sets, would be seeing a subtotal for each fact column in the data set - that changes in line with any filters applied. This would hep developers to check their calculations are returning accurate results - particularly where filters have been applied to the calculation itself using the CALCULATE () and FILTER () functions.