Autos don’t need to be under 12/12, however, during flower as you mentioned, if you do provide 12/12, you should see more consistent bud growth when combined with incrementally increasing (early flower) then decreasing (until 2 weeks before harvest) quantities of nutes. In other words, giving 24/7 light is not a great idea, because plants do like to sleep.
I took a look at GH Flora and it looks like they provide all your plants will need. You will want to make sure you don’t give any Gro solution during Bloom otherwise the plant will focus on producing veg rather than flower, which can cause small buds to appear, and try to provide half or less than the recommended nute quantities and wait to see how the plants respond. If you see rich, green growth emerge, you know your nutes are in decent quantities for your kind of plant. You can also test different nute quantities per plant and keep a record of feeding to compare results. This is what I did last grow and it’s helped a lot this time around!