I was as surprised as Language Hat (Stephen Dodson) to learn that balk may be acquiring a new meaning that’s pretty much the opposite of the traditional one. (I was not surprised, as he was, that the “l” in balk is silent; I’ve always pronounced the word that way on the very few occasions I’ve used it.)
It turns out there’s a lot about balk that’s interesting. For one thing, it’s spelled baulk in the UK. This was news to me, but not completely surprising, because after all the Brits colorfully and flavorfully insert a u in the center of a lot of words.