This is not true in the slightest. We have fired tens of thousands of rounds without any issues. It does not increase wear anywhere or decrease reliability in the slightest. The bolt carrier is not weakened and the carrier does not contain high pressure anyway. We have provided thousands of rifles for LE customers with the exact same bolt with no issues - even with .223 vs 5.56 which has much more effect on carrier velocity deltas than any carrier modification.
The design that was chosen removes less than a quarter inch of steel were the auto sear would contact. The semi carrier is the very early Colt AR15 version. Our instrumentation can't even measure the difference in carrier velocity between the two types. In addition, the heavy buffer adds more mass than has been removed from the carrier.
Our reliability is guaranteed based on tens of thousand of rounds fired in statistically significant samples of this semi carrier compared with hundreds of thousands of rounds fired through automatic carriers.
It is an internet myth that a semi carrier has any effect on reliability.