that's what I don't understand, how can you figure aim without knowing the speed of the break involved?
The only thing I can add is it takes time and experience to properly judge the "dot flow". It's important to find a view that is most aligned with the hole, otherwise you'll be making bad flow reads. Sometimes there are not straight views and in those cases you have to approximate the best you can.
I.e., take reverse view. Lets say your player and ball are to the bottom and right of the holes current position. In situations like these you'll need to ADD more "flow %". If you're on the bottom and left side of the hole you'll need to Subtract "flow %". Obviously a perfectly straight ball to hole view is ideal but we don't always get that.
Anoher tip to correctly read "flow %" is to make a quick initial assessment by breaking down an approximation like so; 25% - 50% - 75% - 100%. So you're asking yourself, are the dots (flow %) showing me 1/4 break? 1/2 break? 3/4 break? 100% flow and 100 break?? From this point you just make an educated guess and make the necessary adjustments.
A 4F putt with a "25% flow" would be 4*.25 = 1FT aim point, or left/right edge of the hole. A 10F putt with a "50% flow" would be 10*.5= 5FT aim point, or exact spot between center hole and 1st row of white dots........so on and so forth.
Hope that helps.