The normal IANAL applies, but I think that once the gag order has been granted, the rest is just details, and is left to FISA as the presiding court. If the argument that the court has agreed with thusfar is: "saying that this action exists harms national security", then why would a judge tell them that when asked directly, they must lie, but then permit them to not lie by omitting a key line in a filing? To answer your specific point, I just don't think there is another court to take this to.