Hi David
PPR does not mean you have to phone before taking off.
It would be quite permissible to fly there and get permission by radio before entering the ATZ.
If you got no answer because the a/d was closed you might be a bit hacked off at the lack of a NOTAM that had wasted your journey.
The airfield owners are responsible for requiring the NOTAM to be published.
They follow ICAO requirements. You therefore get three different NOTAM on three different subjects.
1. Change in opening hours
2. Change in radio operations hours.
3. Withdrawal of the ATZ at certain hours.
It would of course be possible for all of these to differ. For example the radio hours could be less than the hours that the airfield is open or the ATZ could be maintained even though the airfield is officially closed. (there might be some aviation activity taking place other than public use).
To answer your points
"1) Given that conscientious pilots like the chap who opened this thread are still frustrated by the volume and lack of relevance of Notams, are Notams like this any use? "
I would say they are. It is of course up to the aerodrome operator whether or not he publishes them and there is guidance in the Manual of Air Traffic Services on what should and should not be published. Broadly speaking if it might affect a pilot's decision on going to that destination it should be published.
2) Could EGAE publish a more relevant Notam with the actual times, or is the airfield technically open anyway at the published times ? (I was told in strong terms that I must not land, or depart, during the rest periods given to me on the phone).
The Rules of the Air Regulations are the authority here. You are not permitted to taxi, take off, land, or fly in the ATZ without the permission of the controlling authority. They don't have to close the a/d to refuse you permission. It is up to EGAE whether or not they wish to notify you in advance by NOTAM or by changing the published hours.
"There seems to be evidence that many pilots still do not read Notams and the ways to address this are 1) make the software work and 2) make the content relevant. "
1) The software does now work. It's not as intuitive as it could be and it requires the user to take the trouble to learn how to use it but it does work.
2) Relevance of the content is largely down to the originator of the NOTAM and the skills of the user in understanding how to use the filtering tools on the site. AIS do not originate NOTAM, they publish them.
I agree that many pilots do not seem to be reading NOTAM (or more correctly the Pre-Flight Information Bulletins derived from them).
Mike