I've read far too many of these supposed "ontological" type arguments in my life, and while nobody seems to see it, they all contain one feature in common, and it's the feature that eventually defeats them: each and every one of them attempts to hide one single unwarranted assumption, and to then represent that unwarranted assumption as somehow a part of the logical argument. And that unwarranted assumption that everybody's trying to hide is "God exists."
There's an old adage that goes something like: "in order to prove the existence of angels, one must first posit their existence."
But of course, having done that, why bother with the proof?
Of course, none of the ontological arguments ever directly includes the assumption "God exists." They seek to hide that in things like Anselm's "greatest possible to be imagined" (but don't get me started on what I can imagine), or on Hegel's "things that possess 'perfections.'" They are all illusory. The notion of a "perfection" is non-analytic. I can imagine something that has no flaws, but can never demonstrate one. What does it actually mean to posit the "existence of a being greater than any that can be conceived?" All of these things are obfuscatory, but very subtly so, which is why they have fascinated philosophers, and others, like those in RF, for so long.
I say, in every such argument, look for the carefully hidden introduction of an idea which is in fact "synthetic" and pretending that it is "analytic" (or a priori). I am using the words analytic and synthetic in the sense adopted by philosophy.