Were I a Roman Catholic and prone to pondering the power of the magisterium and/or the worthiness of the doctrine of papal infalliblity, and were I of a liberal mind, I would lend every hermeneutic muscle I had to promoting this formulation in the Cathechism:
“Christ . . . fulfills this prophetic office, not only by the hierarchy . . . but also by the laity” (904).
This would confirm my belief that Christ is revealed in the entirety of his Body, not just in the Head, and that with the Body united, the will of God is secure . . . infallible, perhaps.
I would therefore welcome any attempt to discern the will of God as revealed to the laity, not in order to accept it without question, but to listen to that billion-strong voice with humility and wonder.