Having lived for over 100 years, and having practiced martial arts for at least 80 of those years, Cheung 3 Fung accumulated a large body of martial arts knowledge...probably more than any one of his students could absorb. That being the case, did he divide up his skills among his students? I've noticed that each of the Mo Dong 7 Heroes seemed to specialize in a different area of martial arts. Yu Lin Chou (#2) and Yu Doi Nam (#3) seemed to be palm technique experts. Cheung Chui San (#5) seemed to specialize in hing gung. Yan Lei Ting (#6) and Mok Sing Guk (#7) were apparently ace swordsmen (although all seven heroes were well-rounded martial artists overall).
Tai Chi Fist and Tai Chi Sword were late developments in Cheung 3 Fung's body of work, but possibly the most important items in his martial arts legacy. He taught this skill to Yu Doi Nam and Cheung Mo Gei, but Yu was crippled and couldn't practice the art (only comprehend it in theory). Cheung Mo Gei learned the Tai Chi arts, but he was not really a full-fledged Mo Dong Sect member (when he operated in wulin, Cheung Mo Gei worked independently or in the name of the Ming Cult, not as a member of the Mo Dong Sect). That being the case, did Cheung 3 Fung pass on the Tai Chi arts to any of his other remaining disciples, or was it indeed Cheung Mo Gei's responsibility to pass this art down to future generations of the Mo Dong Sect?