Rubbish. They don't know how WC is making their barrels, anyway. Aero sends out light recoil systems, and makes gas ports smaller to compensate for this - WC does the same on some barrels, but not all. Both my .260 Rem barrels had to go up in diameter, but the .338 Fed barrel was excellent.
WC's Intermediate gas system is slightly longer then midlength gas. What I know for a fact: 18" midlength gas barrels with a 0.750" gas block journal diameter require a gas port diameter that's between 0.080"~0.085". You have a shorter 16" barrel, and a longer gas system, so that equals less dwell time. Your gas port will need to be smaller than what I listed above. However, you have an adjustable gas block , and you can always adjust the pressure down. If that was my barrel, I'd be going for something in the range of 0.075"~0.080" for a gas port diameter.
On another note, always, always start a new adjustable gas block wide open. Can't stress that enough.