I’d like to think of that possibility, although it is all theological.
It reminds me of the angels who go around the throne declaring “Holy, Holy, Holy Lord God Almighty as if in each time they went around, they found a new dimention, a new eternal aspect of God.
Ultimately, I would agree with this position.
I would probably question this, since we cannot understand the eternal. If He does not derive from “an outside concept for his conceivability” - then how can we, the outsiders, conceive His capacity. If He is of infinite substance, cannot there be essences and attributes that are equal but expanding eternally in, let’s say, three difference directions?
Obviously, I would be looking at it through my limited mind and through the eyes of a Christian, but I would say it is spiritual substance - but what is that?