That it's not allowed under the CofC does not necessarily mean they enforce it.

I believ e I have on occasion held two reservation on the same flight for a short time, mostly while changing my plans. So the system does seem to allow it. However I never pushed my luck and I typically quickly canceled one of the two.

Guessing what the OP might be up to, just to be safe, I would rather hold two reservations on two different flights close to each other.

(No I don't usually play the game. Except sometimes, even if -or especially if rather expensive, a Tango+ ticket looks better than a Latitude to the people who pay for it...)