I agree with Rikko.
Don't forget that most of the corals we keep in the hobby derive their nutritional needs from a variety of sources in our tanks (fish waste, uneaten fish food, detritus, light, bacteria, dissolved organics, etc.). IME many of them don't require additional feeding beyond that. I consider cleaning the glass and blowing detritus out of the rock work supplemental coral feeding. :wink:
In the event that an animal does benefit/require supplemental feeding (ex. your Tubastrea), I prefer to do just what you've stated - target feeding. IME the negative impact liquid/mush foods, phyto, additives, etc. can have on water quality (and ultimately coral health - ironically) can outweigh whatever theoretical benefits the extra nutrition is providing the coral(s).