I can't see that that is very relevant today. The quality of lights, even down in the sticks is very good, here in Wales at least. If our clubs can do it I can't see why English clubs should have an issue. A logical time to switch them on would be as the players go off for half time. That gives plenty of time for lights to "settle".
IF the regulation is unclear, why not look uk the U19 variations of the laws of the game