I think about 20 years ago it was a popular idea that a growth part of a cycle happens mostly in the night and nutrient accumulation - in a day - and a friend of mine dutifully turned the timer in his plant room into intervals of 4 hours light 4 hours dark. It was supposed to increase the growth rate 3 times. After a couple months he said - it didn't make any difference - and quit doing it.

Otherwise - we all - plants and animals are adjusted to a circadian rhythm - since we are the product of the evolution under the sun. People who work nights eventually develop sleep problems... probably the more complicated the organism - the more important it is - and green one cell algae very possibly is happy to have it 24/7.

Humans who live above the polar circle- buy heavy draperies to close their windows to prevent sun waking them up too early.

AVs - I cannot say anything definite - until somebody will run the experiment - 24 hours in one room and 12/12 in another - with the same care otherwise.

I am sure somebody did - but not necessary on AVs. It can be plant dependent. The plants in Alaska thrive on long hours of the summer - sub-equatorial Africa - day and night intervals are even through the year. People use 13-15 hours per day to stimulate growth and bloom for the show, so it works to some extent.