i disagree with smearing being a sign of bad quality,
after all if you take a walwart .12 and squish it with plyers it will crack and shatter after extreme force.
If you put pretty much any .2-.25 in plyers ( i think ive tried ksc 'perfect' bbs aswell as some local club rebranded bbbastards or ksc or something) and they mush and split along to edges not contacting the pliers with relatively little force. kinda like taking a rolling pin to pizza dough
i imagine that probably directly corrilates to smearing.
if it cracks it wont smear, if its malleable it will.
Physics wise im not sure how malleablility effects flight path. Im sure some would argue the acceleration of the bb would warp it if it were malleable.