This could be the Polyester ball solution. I used an Ice Storm to replace my Blue Dot after about 6 years of service. It cracked around the fingers but it was after throwing it and I'm pretty sure it happened when it hit something in the back of the machine. Storm refused to honor the warranty so my driller plugged the finger area and redrilled it for $15. Now, here's the solution, as such. Plug material is urethane. He did a good job with the colore matching and it even looks like pearl urethane although the cover is polyester.
I if it will crack again because the finger area is not made of urethane not polyester. The thumb shows no indication, so far, in cracking. Had it a little over a year since that happened.
So if it cracks have your driller plug and redrill the thumb or the fingers which is the usual location of any crack, as that is the susceptible area.
Just a thought ....
"None are so blind as those who will not see."