except to say . . . I’ve not found assertions of doctrine clear, or simple . . . on the part of the RCC . . . particularly when considering the whole of the pages available on an issue.
Well, it depends on what you may have in mind as clear or simple. The doctrine of the Trinity is neither, by most objective standards, but it is consistent and free from double-talk. Additionally, I would say it is clear when considered within the framework it is presented in, and is as simple as is possible given the subject matter. The same is true of the Eucharist. The Church simply doesn't teach a physical change and the author of this article implies that such is the case. That is an error.
I think some people forget that the Church has existed for two millenia. That is a very long time. When we read Shakespeare we know he made perfect sense in his time, and yet we have to have footnotes and dictionaries to make sense of him. Was he unclear? No, but we are removed from his meaning by generations. The same is true for the Council of Trent, and we are even further from St. Thomas and others who contributed so much to the language the Church has used in understanding such mysteries. Terms like accident, substance, species, etc. are all so much gibberish to most of us, but were otherwise at the time they were used or when read by scholars. Given the difficulties inherent in reading and understanding the Nicene Creed I would say the teachings of the Real Presence of Christ in the Eucharist are actually quite reasonably clear.
Thanks for your perspective.