I don't have any problem w/ adding light in increase egg laying in the winter, though I do not do it. The only caveat to that is this, a bird has xyz number of eggs in her to lay during her life, she will stop when she meets xyz number, if that happens in 2 years or if that happens in 6 years. In all likelihood birds that are induced to lay more will burn out earlier, which is fine as long as you prepare for that in your husbandry practices and have an "outlet" for spent hens.