The statement from Crux and from online about crack fixes seems to imply they had good support, albeit a clearly shitty product if so many people were sending in cracked suppressor sleeves. Regardless of that fixing and returning a cracked suppressor in 2-4 weeks was completely unheard of, yet Crux was doing it for a while.
Turns out it was unheard of because it's very illegal, and Crux was just replacing cracked sleeves with new ones and copying the serial number. That's a BIG no-no in the eyes of the ATF, you need to either repair the original or create and transfer (with a Form 4) a new item with a new serial. What was happening was too good to be true, and the company (and its customers) is paying the price for it now.