Just to clarify, OpenSprinkler does log the flow rate per station. However, as Ray said, if you run more than one station at a time, the flow information will not be accurate.
But if you are like most people and run stations sequentially, the information is there.
Check the API document, the “jl” command returns the OpenSprinkler log data:
Here are the columns returned from the API request:
program ID, Station ID, dur in seconds, end time, flow rate during the station run
Here is an example record showing a flow rate of 13.27
It would be great if this data was shown in the UI with the warning that it should only be used with sequential zones.