Perhaps "entering a NOTAMed gliding area (or area of NOTAMed intense gliding activity)" might be more appropriate phraseology, rather than "Infringing", which would cause any pilot some consternation.
At the end of the day, as far as gliding activity is concerned, the whole of class G, plus some extra airspace, such as that near Dunstable downs and embedded in Luton's CTR, requires the same "see and avoid", NOTAMed or not.
BTW, anyone can put forward a NOTAM. I discovered this some years ago when I rang the contact number given on a NOTAM. The person who had put it forward was a chap flying birds of prey to and from a tethered kite. I explained that I often needed to enter the given area to gain access to a landing site. He insisted that I must now avoid "his" area by 3nm and 2000ft! The NOTAMed area for launching the kite was itself 3nm in diameter (he varied it day by day), so he reckoned he was entitled to a 6nm radius "sterile" area all to himself. I pointed out that he unfortunately had false expectations because even his local airport, operating large airliners, only had a 2.5nm ATZ to protect it.
Another kite flyer had a permanent NOTAM put on one of my regular routes, right in a choke point where airspace required us to descend to 1500 feet QNH. I rang the contact number to find out more details and the kite flyer's partner answered the phone. She told me the kite flyer was at work and she couldn't remember the last time he had been out flying his kite, it was months before.
I rang AIS to advise them of this. I was told if a NOTAM was submitted in the correct format they had no option but to publish it until it was withdrawn by the applicant.