What I've understood, the plant produces flowering hormones in the dark, and the longer the dark, the more hormones to flower, and anything greater than 10 hours dark, can be too much hormones and start them flowering. (Photo plants)
So yes, you can do longer darker periods, as the plants flower, and it will help with promoting flowering.
As long as you give enough light in the light on period, the DLI, you are fine and not hampering your growth or flowering.
So slowly bring the tent more into darkness, will help simulate the natural effects of season change.
This is why an 2 hour power out, in the middle of the light on, can mess with the plants, and give to much of the flowering hormone.
Again, what I have discovered and can be wrong too.