Kahr has said, and demonstrated at a gun show for a fellow GT member here, that they can grind or cut that part off and the gun still functions 100%.
The crack is cosmetic, but Kahr has honored the warranty repair for others, even when the gun is a few years old.
You have to call Kahr Monday morning and ask. (Number is on their website)
NRA Life Member
The scariest words in the English language: I'm from the government and I'm here to help! President Ronald Reagan