What on earth do you mean by “using Papal infallibility?’ What do you mean by ‘opined’?
Pope St. John Paul 2 declared in Ordinatio Sacerdotalis that the Church had no authority to ordain women. Pope Benedict XVI declared that this declaration of Pope St. John Paul 2 was to be accepted as part of the magisterium and held as an infallible teaching.
If something is already known to be part of the deposit of Faith, an infallible teaching like the Trinity, the sacraments, the Assumption, etc., there is no further need to make an ‘ex cathedra statement’ about it.
So I can’t understand why you would expect ‘more’,
