We will be measuring flow and more than likely incorporating some calibration feature to help dial-in custom nozzles. Assuming if we've calibrated zones and know expected flow per duration, not a far jump to know roughly how much flow we should see over a given period.
This is all speculation at this point. The nice thing about sofware is the answer is usually "yes", it's just priority and is this feature widely asked for.
Thanks for the feature request, hope this helps.