Well, two comments then:
The Original Post mentions none of those three things, but adduces the relevant verse of Ps 69 as dispositive.
Therefore it seems to me that the whole method is indistinguishable from a projective technique. Those who think the “perpetual virginity” of Mary is not true will find proofs here and elsewhere. Those who think it is true will do ditto.
I’m not saying it IS a projective technique. I’m just saying I don’t see what one can point to to show it isn’t.
“You know my methods, Watson.” ;-)
LOL.
I know. Have seen that so much.