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This Regulation shall be binding in its entirety and directly applicable in all Member States.
Done at Brussels, 6 April 2016.
From your own link
Member states have the choice to derogate or not but as stated the regulation shall be binding in its entirety
That does not mean part of, can be selective or reinterpret definitions which are already clearly determined and defined by EASA
Commercial is already clearly defined and does not mean pilots being paid to fly private aircraft.
It is the entirety part where I think the CAA would trip up on their latest home made interpretation of commercial.
Strangely we made a challenge on validations based on what was commercial or not commercial and i have a letter from the head of CAA stating the mistake and that we are non commercial in our operations so they change opinion year to year
I personally feel there is a solid legal challenge potential there but will need to get advice. They have made wishful thinking mistakes before in my experience