I dont get the chan wah shun is wc and leung bik is TWC. They learnt off the same guy, leung jan. Talking to people in hong kong they say china does the wong wah bo stuff, talking to main land they say they are doing the leung bik stuff. Gwok fu talked about the changes he made to their teaching when he got back from china. Whether it was leung bik or just Yip man getting better we will never know. Things like the pheonix fist which is still in main land but yip didn't teach it in HK. The change of the garn sao in the last half of SLT. He learnt garn sao off chan wah shun as he was tall but only taught jum sao in hong kong as this was from leung bik and he thought it more direct, hand closer to target etc.
Only through WSL fighting did it come back to the system. With the WSL system doing both in SLT.