Is seems to work better on WLD not to give supplemental light durring the winter. When i was lightning for 6-8 hours and bottom heat in the low 70s it brought on WLD. Now i have stoped this for 2 months now and every citrus seems to be happy. They only get the morning sun 4-5 hours when the sun is out. This year when they go out side i'm going to only have them exposed to morning sun 6-7 hours and see how well they respond not getting the cooking afternoon sun. last year they were in full sun with container protection from the hot sun.

It's often said, that WLD is caused, because of light.
Thus illumination is benefical, if the roots have a temperature on around 75° F, but it's not neccessary.
All my plants are grown facing south, so getting full sunlight. WLD was of concern, before bottom heat was established, now the bottom heat keeps the pots on 73° up to 74° F, and WLD is absend.
No extra illumination is given, because sunlight is doing all illumination and it's ok.

I only face problems in March and April, wenn first spring comes up. When I forget to switch of the bottom heat, the plants quickly suffer, because spring sun and bottom heat rises the temperature to high in certain pots, thus again leaf drop occurs...