@Comment. Thank you for your explanation.

But you merely re-iterate the Pope's text. Which I have already described as internally contradictory . Perhaps if you were to provide specific examples of "unity of ...practice, (with) various ways of applying it..." I would better understand.

The word used by Pope John XIII in his announcement speech some 3 years before V2 began in 1962 was aggornamento=updating. Initially specifically used about the Code of Canon Law and only later as a synonym for the whole V2 Council.
The old fashioned phrase "deposit of faith" used by John XIII in the quote above is, for me at least, indicative of a praxis a million miles from the current confusion of "Malta & Buenos Aires (but not all Argentina) vs Kazakhstan, Poland and Portsmouth in England; with Cardinal Vincent keeping a typically low profile" which is the the current situation and which Pope Francis seems only too happy to endorse
¿ Can two contradictory truths co-exist; still less set me free ?