Thats because indoors there is less dirt so it tastes better. But outdoors it gets covered in dust, hairs and everything else thats floating around. But if you do bud washing in a pail of water with a little baking soda and lemon juice you will immediately see all the nasty stuff coming off your buds indoors or outdoors. And bud washing doesn't knock trichomes off, its been tested. Once you have washed your buds once you'll never go back after seeing all the nasty crud thats stuck to your bud. I shutter at the thought of smoking it. Anyway with full spectrum LED you should see no difference inside our out, the only thing the sun has is powerful UV-A and UV-B which just damages the plant which can potentially lead to more trichomes but often is shown not to.