The Introduction Into Service process is very laborious and rigorous, and if the re is not an Airworthiness Instrument in place to allow certain activities, then that aircraft will not do it.
An Army unit wished to do a helicopter insertion from the carrier onto Beecroft range 25/3/72 and the RAAF were unable to provide support because the Huey didn't have clearance to operate from ships.
I spent 24/1/73 sailing in circles on the HMAS Moresby in Jervis Bay while Bob Treize of ARDU cleared the Kiowa for shipboard use. The only wind was that provided by the ship and pitch and roll never exceeded 0°. What a waste of time, but it ticked the boxes, and none of those that might interest a naval aviator. And none of it was Bobs fault, just the system.
We went on to learn on the job.