Woodo., you are right in underlying the difficulty in attributing the right numerical value to each break line. That is why rating the speed of the travelling balls has to be done with a minimum of rigor with a keen sense of the pace of ticking seconds. 10 seconds = 1, 8 seconds = 2, and so forth. I will try to map this in my future update.
Do note that suncity. (an outstanding player) has confirmed to me that his approach is similar to mine, and his "feel" of the putts comes from a long experience of making the right gauge, based on the travelling balls indicating break. Sure, you can go on instinct, if you don't care to refine your method, but ultimately the scope of your success will be directly proportional to the scope of your efforts.
Incidentally, do note that my 1.43 putting average would be more like 1.38 if I could ding the darn putter more consistently. My compromised physical condition is a limiting factor I have to live with and accept gracefully.