The cracking issue w/YYJ has been around a long time. It’s primarily due to unequal expansion and contraction of the metal rims and the plastic body. The metal rims constrain the plastic shell causing stresses to build in the shell. Stresses cause cracks. It doesn’t happen in all cases. I have quite a few metal rimmed YYJs. Some have cracks, some don’t. It has nothing to do with tightening. Overtightening just loosens the metal insert the axle screws into.