Its fine to control day/night cycles by taking plants inside and outside if that's what you want to do. As mentioned, you do have to make sure they are truly in darkness if you want them to flower.
Supplementation on cloudy days with artificial light is OK, though probably not really necessary. Even "cloudy" days typically still offer lots of light of good spectrum.
I'd offer the following additional two suggestions:
-If you are also growing dedicated indoor (only) plants, its not a good idea to bring outdoor plants into your indoor garden, since its a surefire way to introduce mites and other pests.
-Bringing younger indoor grown plants suddenly outdoors where they can be exposed to potentially high levels of UV light can damage them. Its better to acclimate them to outdoor sunlight by gradually increasing hours per day exposure over several days or longer.