There is enough work to do attaining a good level of proficiency in Ving Tsun without adding other things. I never question myself for training so much and not "proving" it out in the ring. I don't care about all that garbage.
I cannot allocate any more time to training than I do per week which is around 7-10hrs. 4 of them will never be spent learning BJJ thats for sure.
If people care about competing with Wing Chun then its up to them in which case they can add what they want. One thing is for sure. They better train like an trojan instead of thinking that superior Wing Chun beats all. Most of it is rubbish.