in my practice, I usually present Waterfall charts using positive amounts and manage their direction (up or down) by calculating the offset accordingly. This way, all bars carry positive numbers, and the numbers are always presented on top of the bars.
You can also try experimenting with Dual() values - your numeric value can be positive, while text representation may look like negative.
Finally, you can experiment with an extra set of Expressions - those with no visual Representation, except for "Values on Data Points".
I am using native Qliksense Waterfall chart Nov release . I have formatting issue for subtotals when i use formatting as Measure Expression . When i format to number i get negative values while i subtract to get subtotal. I Multiplied by -1 and used subtract it screws up subtotal. Any other ways on how to show subtotal total number (currently is shows 1.5k ) it should represent a number like 1489 ..