Without EU membership you may comment proposed changes to the basic law but you won't have any MEPs or ministers or commissioners having a say in it. So the CAA would be no better off than Joe Pilot writing a comment (though their comment might get more attention).
Not that EU membership, nor MEPs, ministers nor commissioners allowed any input into the drafting of EASA FTLs anyway!
To the detriment of safety.
Precisely (in a nutshell) why a majority of my country, the fifth largest economy on the planet, the EU's biggest customer, and second largest economy currently in the EU, wants no further part in such an undemocratic, wasteful and out of touch organisation?