. . . .That doesn't seem to be case for everyone... In fact, it sounds like you are using bong-sau, to actively redirect force... Is that correct?[ QUOTE]
Of course, why not? You attempt to do that when you roll in chi sao. Moving your arm from tan to bong, you test your partner's position with both hand positions, and if it is weak (opening up the center) or incorrect, the bong just like the tan, changes to another hand position to strike (punch, dim jern, biu jee, whatever) or destroy their position, structure, base, whatever.
You push forward with your tan sao, why can't you push forward with your bong? You can, just not so much as to over-power your opponent with it. Just to guide or re-direct their energy.
A lot of people use the translation for bong sao as wing arm. That just tells you what it looks like, not its function. I use the terms guiding, trapping, or pinning arm which tell you more of what it is doing as opposed to what it looks like.[/QUOTE]
A translation I have heard for bong sao that I like and use is flanking arm
In fact I think all the arm/ hand positions in WC are descriptive of what is taking place not what it looks like.
Another example, I use tan sau not as palm up hand but as dispersing hand.