This idea comes up regularly. The pope, in the church fathers is the most correct. I suspect translation issues in some of the quotes.
In the original language, it doesn’t say “sins” as in once – rather it uses the present (continual) tense in Greek which means a repetitive action done in the present (and will be done in the future, when that becomes the present…)
Those who CONTINUALLY blaspheme the holy spirit can’t be forgiven in this age or the age to come; they are (by definition, even) guilty of an ETERNAL sin.
They can’t be forgiven while in the act of doing a sin which they KNOW they are doing. They can’t possibly claim ignorance.
I had never seen the idea of attributes of God being used to assign the type of sin to the blasphemy; (or I don’t recall reading it if I did) but that makes very good sense to me. Thanks for posting that!

I learned something new.
As a side note:
The pharisees were
continually persecuting Jesus for good deeds he did; whether to the lame man on a Sabbath, or the blind man, or any man or woman on the Sabbath…! This is what he found irritating – that they wouldn’t quit doing it. If they would STOP, he could forgive them – but they wouldn’t stop, all the way to the cross…