The smoother the rind the better off you are. All those little cravases leave places for molds and other bacteria to hide and ruin your cheese. I would trim it off before sealing.
There could be several reasons for a cracked rind. Drying to quickly, too wet, a build up of internal gasses releasing. Contamination of the cheese. Cheddars do not generally produce excessive amounts of gas unless something was introduced to the milk/cheese to contaminate it. As you made two wheels and one is fine and the other is not it may have been you did something when packing the curds into the blown cheese mold. I would watch it closely and not seal that one for a while.
