I disagree with that author then. The issue IS settled. The moral theology foundations of these principles regarding licit use of NFP, on which you and I are 100% in agreement, are solid.
All that remains is proper catechesis.
I'm still waiting for the list of Popes, and what they said.
It seems 'grave circumstances' has become the crucial phrase in this discussion, which means you are now hiding behind it, as it covers only very limited circumstances.
I personally am willing to concede 'grave circumstances'. I always did.
But I put to you that the majority of Catholics using NFP do not qualify for 'grave circumstances'. It has become a way of life in order to stop having babies.
Now it's certainly not up to me to decide who qualifies, and it is cetainly not up to you to lure people into using it with a clear consience. Your actions could be a cause of sin in others. But apparently that is your goal.
So, please give us that list of 'quite a few' Popes you falsely claim supported "ex cathedra" that Catholics could limit the size of their family.
And if you could, maybe a list of grave circumstances that would be acceptable. Maybe if the husband or wife were on life support, in a coma, the other spouse should wait for a non fertile moment to demand their marital rights. I guess that would be grave enough.
List of 'quite a few' Popes and what they said please.