SAP Limitation - Not possible to add subtotal on collapsed report

When creating SQL report and using the grouping/collapse level functionality, is it not possible to incorporate subtotals into this due to SDK limitation (E.g. add a subtotal line each time the grouping changes, e.g. total dollar value by date, etc.).

We have asked SAP for this feature but if you would like to express that you also want it then please vote here: https://ideas.sap.com/D31207