Regarding the point that governments may not wish to reveal the existence of the UFP to the general population, I think that the UFP should not listen to those governments, but rather consult its observation teams, asking them, not the governments, whether the population seems ready. If the OTs say yes, but the government says no, the government should be ignored.
Oh, really? So, in other words, we should ignore their sovereignty and violate the will of the legitimate government of the planet being contacted?
I'm sorry, but that's the very definition of a violation of the Prime Directive: You are robbing that culture of its right to make its own choices through its legitimate government.