Bob
There's nothing illegal about the procedure as published in the aerodrome manual, just needs a bit of prudence in its application. I can normally make 500ft in my trusty steed but I've got 50hp more than what you're teaching in. Possible solutions are teach short field / max climb from that particular runway and normal departures from the others. The other option is possibly for the airfield management to only use the other 3 runways unless absolutely necessary.
I do know that the phone gets VERY hot with complaints on a busy summers day. Maybe it's time for the users and airfield management to get together and have a rethink. 03 I suspect could do with being right hand for noise reasons.
At the end of the day there are more people in that estate that can complain I suspect than possible airfield users, and we have to be good neighbours. The turn before the houses I agree is not ideal, and can be risky for a low hours student. I think at the end of the day it's up to those of us qualified and able to operate as sensibly as possible so that if the students end up going further than the rest of us the 'perceived nuisance' is minimised, if not removed completely.
CM