I direct feed several corals because they are non-photosynthetic. I also sometimes feed my regular stuff like acans, lobos, etc when there is left over mysis in the seahorse feeding dish. I will also spot feed my inverts and hit the sps too while I'm at it just because it's the right size food for them too. My tank is well established and handles all the feedings very well but in a newer system I would start increasing any food slowly and watch your tank params. Part of what I love about keeping coral is watching the different responses to things like food
Edit: by inverts I mean my tunicates, basket stars, feather dusters, etc, not snails, that would just be silly!