Currently the Waterfall Chart can create Interim Balances, but those are calculated as part of the chart.
In case the actual data set already provides those interim balances and Final Balances, those can not be leveraged because as soon as the Interim / Final Balance flag is set, the actual data value is being ignored.
There should be an option to decide if an existing entry from the data set should be visually represented as Interim / Final Balance.