GREAT!!!!
While I know from personal experience that the 1/2" x 28 TPI has worked well for dozens of M14 shorties I've done my self, there have been some concerns that THEORETICALLY, the small diameter 1/2" thread at the muzzle might cause some accuracy loss.
Practically,
experience has shown that M 14 shorties with the 1/2" thread are still capable of superb accuracy,
but here is a case where BIGGER is BETTER just might be true.
If the 14 X 1 mm thread is PROVEN as viable for M14 muzzle accessories,
I WOULD SWITCH OVER TO THAT MY SELF.
Good luck with your experiments,
LAZ 1