Yes, they do crack, well at least the touring models in SoCal conditions.
My Maxima had BFG Touring T/A that were 10 year old and had cracks, even a few bigger ones on the thread, however they held together, unlike Fisks half their age which in 4 years of use developed tread separation.
The Corolla has BFG Premier touring T/A that were made and mounted in 2009. The tires have microcracks in the sidewall and the transition area, but have held up great otherwise. They have over 105k miles but they have very little tread left, well past the point of recommended replacement.
I've also had 2 BFG Touring on a Camry, used for about 2 years before I sold the car.
IMO the BFG touring tires are loud, hard, have little grip in any conditions, develop microcracks, but they do last, and don't develop structural flaws.