So this has probably been addressed, but it feels to me as though the "only the first feather proc" counts deal is false. I feel as though every fruit counts, but the message is only indicative that the fruit you just fed puts the RGB at a value that will be a different color from what your chocobo is. Which is why it is possible to get the "feather proc" message, and then not get it on some subsequent feed. Sometimes it takes a good deal of fruit because there are many RGB values that are not valid as colors, so it might take a while until you get to a valid one.