EGJA is NOT class A airspace....Class D from SFC - 2000' (Alderney CTR).
Channel Islands CTR is Class A, and you do need a specific clearance to enter. However once at Alderney, the Class D up to 2000' encompasses Alderney and Gurnsey.
I have been to Alderney several times, and must admit never requested 'start up clearance'...and have never been b@llocked for it
Nice place though, good curry house, and pubs. Jersey is also a good day out. Very easy to get to, routing from EGHH....EGHH NEDUL then THREAD ORTAC, on the SAM 208°R. Bournemouth radar, then (possibly) London Info, Jersey zone 10nm N of ORTAC, Gurnsey Approach, Alderney tower.
Cheers
EA