I’ve had an excellent response from the Northumberland National Park’s Visitor Development and Marketing Manager, who’d received assurances from NCC that harmful LED lights would not be used. At that time 4000K was thought to be OK for wildlife locations and that’s why a concession was made for the National Park. (We now know its not and the target should be 3000K).
Which begs the question “If they knew 5700K is unsuitable in some way for natural environments, why has it been installed across all NCC residential areas?”.