Newmarket Holidays could charter in an Avro RJ, Embraer jet, Airbus A318 or even a lightly loaded Airbus A319 to operate
Unfortunately the laws of physics don't change with aircraft size and when the wind requires use of runway 03, any aircraft would have to make a tight turn on to final at 300ft or less.
The only way to avoid that is to schedule all your flights to arrive at Lydd in the late evenings and/or weekends to avoid Lydd Range activity. But even that's no guarantee because it's a 24/7 range with frequent short-notice changes of activation.
Best of luck to them. They'll need it.
NS