I've fed mine flakes sometimes. Ime they like flakes just fine if they like the taste of the product. There's no need to soak, pinch, etc. if you just release the flakes into your filter current to blow them around. Not only that, I also feed mine freeze dried mysis, a floating food, and they do just fine going after it.
Ime with sveni and other geos, if they like a food they'll go where the food is, especially if they're comfortable in a tank, not intimidated by other fish, etc. Even for sinking pellets mine come right to the surface and snap half of them up before they ever hit the sand, then they go sifting for more. I've had zero issues feeding 2-3 mm pellets to geos, not if they like the product. My main reason for feeding smaller pellets when they're available in a particular product, particularly to smaller geos, is it keeps them busy for a while vs. filling up quickly on a larger pellet.