I'd imagine that with Alasgun's gardening life, timing is everything.
I have also imagined in the past that vining crops may not require as much sunlight as many other plants. It would be sort of crawling out of shade to reach the light, in the 3 Sisters Garden, that sort of thing.
"Supplemental lightning" is all I have used, in the South Window and in the greenhouse. With some springs it would be a very good thing to have it as a regular thing because of the cloudy weather that so often sneaks across the mountains from the Pacific Coast.
Full on lighting during Winter would be required indoors for even vining crops, if my guess about them is correct. DW is able is sustain the lives of her houseplants, sitting in Winter windows but that is about the extent of it here at 48°N. One thing, the low angle of the sun helps with a more direct access of sunlight. Spring sunlight may provide more hours but light reflected off vertical glass becomes rather extreme as the Summer solstice approaches.
Steve