The problem seems arbitrary, the very nature of the Overvoid means everything in DC including the Presence is it and the reverse anyway even if it's contradictory. That there's a dozen different avatars or equals or manifestations or aspects or Michael+Lucifer(+Gabriel?) or whatever of the Presence while also sometimes seemingly being the actual supreme being with no equals just reinforces the illogical dream/story logic nature that the Overvoid is operating on, because "omnipotent" characters and concepts tend to throw logic to the wind.
Yes, this sounds dumb because it is, but it's a built-in excuse for contradictory stuff when writers write or say contradictory things about this subject unless some DC writer directly changes the nature of the Overvoid, and I don't think that's happened or is likely to happen for a while.
For thread purposes, I agree with Matt, the Presence has too many problems with the whole "not being fully Omniscient, having equals in power, admitting he's not Omnipotent and that he was created by another, being defeated and threatened a few times, and even temporarily killed" thing, and it's not just the case in Vertigo, these things have happened in regular DC as well several times, so he should stay 1-A.
Maybe we should merge The Writer and Overvoid page though, since it seems more like they're both parts of the same process. Could be fun to see since it might be the only profile with two tier 0 keys, which would kind of look like 0/0, which is pretty appropriate for a Tier 0.