You AGAIN pick another poor example of a Korean MAists!
S. Henry Cho: Wrote 3 books on Karate! 1- Korean Karate, 2- Better Karate for Boys & 3- Self Defense Karate
GM Cho can be described as umbrella TKD or WTF TKD, as he helped them form & help with the tournament sparring rules.
His training was at the JiDo Kwan, which was a ShotoKan deriviative or Korean Karate. The JiDo Kwan was a major influence in the WTF & the rules that helped distinguish what they were doing from the hated Japanese Karate.