There's nothing particularly wrong with what you're saying there but that's because a wide range of things work, for instance, if OM47 finds that doing his daily feed in the evening works, I'm sure he's going from experiences that have made sense in a lot of ways.
Size of tank, number of fish and amount of plant cover make a difference too. For me, I'd find what you just wrote to be too extreme on the stingy side. I have plenty of plants that will happily consume the little excess food that makes it down to the substrate. My fish will also get pleasure at being rewarded a little in their all-day search around the tank, so I don't mind a little extra food, but not a lot. I put the potential time-period more at 2 or 3 minutes of eating, not 30 seconds, although I'm sure its often around 1 minute if I timed it. Just depends of if I'm relaxed or in a hurry. With tiny tanks you do need to be more stingy and careful, although good maintenance habits should really take care of all problems in this area.
~~waterdrop~~