Just a few examples:
(1) Traditionis custodes lays down (2:3) that the reading at Mass should be "in the vernacular language". But the Vicar of Rome ... a town where, in the past, Catholics from every country in the world have often gone on pilgrimage ... has laid down that the readings should be in Italian.
So a priest leading a group of his own folk who do not understand Italian really has got to struggle through two readings in a language he does not himself understand and will not pronounce correctly, for the benefit of a congregation for whom this silly performance will be pure gibberish.
We also have here yet another example of Italophile imperialist arrogance; the mentality which de facto treats Italian, rather than Latin, as the official language of the Catholic Church.
(2) PF laid down that "everything that I have declared in this Apostolic Letter ... I order to be observed in all its parts etc.. But the letter of the Vicar for Rome informs his readers that one of the articles in the Motu proprio is "not being activated" in Rome.
Unlike PF, who wanted every word of his decree to be activated immediately, in Rome itself, apparently, this legislation has to await the say-so of the Cardinal Vicar to be "activated".
(3) The Cardinal Vicar neatly explained that such other books as the old Rituale are now forbidden. But, in his letter to Vincent Nichols, Arthur Roche replied to precisely this question with the words "Traditionis custodes speaks only of the use of the Missale Romanum of 1962 and Eucharistic celebration."
I am sure that canonical experts must have discussed the situation arising when an apparent 'law' is so badly drafted as to be incomprehensible, or impractical, or manifestly contrary to the good of christifideles.