I am quite confident your diocese has one. It is a person…sometimes it is a priest although it can be a deacon or lay person who has completed studies in ecumenical studies and ecclesiology…who serves as a subject matter specialist and a resource specialist.
You would get far better answers there than you are here.
Answers that will not be simply citations of documents – which have to be interpreted in light of subsequent determinations in any event – but actually where we are in 2017.
That is why, today, we are jointly commemorating the Reformation. We have been planning this for years, since the Pontificate of John Paul II. It was important to all three of the Popes that this be a joint commemoration, for the first time.
Something that not only did not happen but was simply unthinkable in 1917. From the perspective of both Lutherans and Catholics equally.
How we got from October 1517 to October 2017…and most especially the events of the past 50 years…is a really remarkable and wonderful story. Some of us were fortunate enough to have lived it.
You have read From Conflict to Communion and Declaration on the Way? You would learn more there than in the posts that end up here. The former document is, in no small part, the reason that Gerhard Müller, who was then Bishop of Regensburg, and Kurt Koch, who was then Bishop of Basel, were brought to Rome and why they are Cardinals today.