I think most drip systems publish GPM and GPH.
One more thought on what is certainly a corner use case scenario: A few years ago I set up a flood and drain hydroponic system with an AVR controlling a fountain pump for the fill cycle. It was very crude compared to OpenSprinkler. As well as being amazed at the accelerated growth rate possible with hydroponics, I found myself constantly having to increase the fill frequency and duration by small increments almost daily. I could literally watch the plants start to wilt and revive as the pump cycled. A simple slider for fine tuning zone time/water amount would have saved me a lot of repetitive hand coding.
Ultimately the hydroponic system had a catastrophic failure (for the plants) due to a missed watering day. There is absolutely no room for error in that type of system. Growing in soil may be slower, but it is much more forgiving.