We use Varistream controllers which don't have the fine adjustment the Spring controllers do.
So I have a choice of 3, 4 and 5. I don't know if these flow settings are similar to 30, 40 & 50 on Sprng controllers.
I use a 5.2 lpm Shurflo pump with 100 meters of minibore hose. For my setup 3 is a little less than 1.5 lpm, is a little over and 5 is closer to 2 LPM.
For me 3 is the idea washing phase as I get enough water to wash the window without wasting water. It doesn't provide me with enough water to rinse with effectively. In other words, rinsing takes too long.
4 provides too much water in the scrubbing phase and whilst it gives a better rinse it is still a tad too slow for me.
5 is a total waste of water in the washing phase but gives a nice rinse speed for me.
We have plenty of water since going the 4040 route, so I usually work with 5 but I know I'm using more water than I would on the same houses with a slower flow. I'm not sure how much time a quicker flow saves me during a day's work. For me its probably minutes rather than hours.
As M & C says, your water flow is going to depend on how fast you can work and also what type of windows you are cleaning. Age is against me so I'm slow, especially when I see the rate at which some younger ones can work at.
If we are cleaning older sash windows in poor condition, I also slow my flow down to 3 and spend very little time washing and rinsing. Its not a flow rate I would use on UPVC windows.
Now if you wanted to compare the flow of cold and hot water with the same setup and same controller, you will notice a big difference in flow rate on the same controller settings.
Your situation is going to be different as you are using pole hose on your hose reel which has a smaller id. Again, as M & C says water can only be pushed so fast down the pipe. Once you get to that point running your pump at a higher pressure isn't going to achieve much more. So your figures will be interesting.
.