Another thought. I'm not a fan of any Baat Cham Dao form that has a lot of blade flipping movements. In my book, Wing Chun is supposed to be pragmatic and efficient.
In fact, I've pretty much concluded that the way most people train the knives (especially in my lineage) is pretty useless ... you know, waiting years to learn an arcane form, practiced in secret without extensive paired drilling, or some form of free training or sparring/fencing against an opponent... working on distance, timing, angles...
Yes, I do own a couple of pairs of BCD, and once I knew most of the form, but I don't train it these days. I'm not a huge fan of knives for defense anyway, but if I ever had to use them, I'd fall back on my Escrima training. More practical, in my estimation.
Now some say the whole point of the BCD is the footwork and movement. Well, I do practice that, but in an empty hand context. It just makes more sense to me that way.