Coach Yan helped me to understand the basic fundamentals of of modern footwork and technique. I still use some of his principles today.
Although i think the Sweet Spotter would help me achieve pinpoint accuracy on contact, in the overall picture, i dont think it will work with, and possibly hinder, my modern style.
A lot of us hit with a high spin technique, and use a lot of areas of the stringbed, not just the sweetspot. Depending on placement,swing and depth, i vary contact between 9, 3, 12, 9-3, 5-11 o' clock, etc.
ie. if you rake the ball across 3-9, its not going to matter if you hit the sweetspot, because youre not intending to anyway.
Modern technique is far more complex than just hitting the same spot, everytime, on the stringbed. But i can see where this would greatly benefit flat hitters.