NLM have interesting remarks about Abp Ranjith incorporating EF usages into his personal celebration of the OF, such as two genuflexions at each consecration, and what the 1960s radicals disparagingly called 'finger-pinching'. Although very much a non-canonist, I would have thought that what the Secretary of the CDW did ought to be able to stand as forensic evidence of a usage being permissible. What seems even clearer is that what the Pope does must surely be ipso facto licit since what we are talking about is the Roman Rite and he is the Bishop of Rome celebrating the rite of his church. (And I recall an episode when Old Marini told John Paul the Great that he should be standing and JP2 replied 'The Pope is kneeling'!)
One thing I have in mind is the practice of joining one's hands and bowing one's head at 'Let us give thanks unto the LORD our God', which Benedict XVI did at his inaugural Mass despite the fact that according to the OF rubrics the hands must stay extended. I regard this as a very beautiful act of reverence for the great Name of God.
Perhaps the fact that High Authority openly hopes for the EF to resacralise the OF creates a new situation. I nominate the Silent Canon as the next EF usage I would like to see creeping stealthily into the OF.