This is what I did years ago...maybe it will help you, maybe not. You want to strive for shooting all shots at the same speed. Of course, you can't succeed at that , but the majority of shots can be shot at a certain speed. When you know that speed, and have it set subconsciously, then you can start to learn what the cb reaction is with different tip placements.
Most shots, I want to be about 3 diamonds from the ob. Gives a little leeway in speed control and position play. Knowing that, I know exactly where to hit the cb to get a stop or stun shot from that distance at the speed I normally use. From there, you can go down one more tip from a stop shot, at the same standard speed, and learn how far the cb will draw. Then do it with two tips lower.
Now, you have a standard to go by. If you need more draw, you just apply more speed. Takes practice, but it gives you a baseline to go off of. Of course, you have to hit the cb precisely, not just where you "think" you are hitting it.