The ability to know the amount of water that has flowed through the breach for each time-step and in total.
Like an OBJECT_FLOW_OUTPUT attribute linked to the breach or breach input area, like there is for inlets, pumps and culverts.

Additional information:

https://previewsupport.tygron.com/wiki/Object_flow_output_(Water_Overlay)

https://community.tygron.com/forum/discussion/comment/793#Comment_793