technically, this can be done, but the problem is that doing this will confuse the living hell out of your gals or guys, and it will take a notable amount of extra time, and after you switch back to 24hr. the growth that does occur will be slow and look goofy as shit, twisting, turning, and deformed looking foliage. they can also get stretchy and the new leaves will be more rounded without the usual serrations.

with all that being said, some people have found that revegging can be used to their advantage. In 'Monster Cropping,' a clone is taken from a flowering plant and put back to veg. After a few weeks of stunted and funny looking growth, the bud sites will shoot out more branches. Heres an article that explains it a bit better

Re-Vegging Cannabis ("Monstercropping") | Grow Weed Easy

so in short, it depends on your particular situation. if u have the extra time, maybe try it with one or two plants to see how they do. if you want to do some googling, just search 're-vegging' or 'monster cropping'

Hope this helps!