I have the facsimilies of these three books and find them to set excellent standards.
an example of the early gothic shown here
, while being a particularly nice specimen is approaching a point where it is barely within the orthodox western iconography standards, perhaps just barely...
Of course it takes some study to find these examples, a specialist should be appointed someday to do this.
Yes, this is a very academic approach, but what else is there to do? It would serve the Church well.