From looking at pics on web I don't think anyone is following the Allegro guidelines.
The Sparkfun and Pololu boards do at least have large through holes for screw terminals which basically forces you to use large diameter cable as the heatsink. All the others seem to be random PCB sizes.
On mine I have removed the screw terminals and soldered some copper braid tails. I think I'll also run with a shunt to reduce the through current until I'm confident that it's working OK.
