“would the atv do more harm than good spreading in the morning and evening before each hunt?”
No, the wheeler is much better than hand spreading corn. No scent, in and out quickly and the deer respond to the “corn wheeler” rapidly. It is not unusual to have deer feeding on the spread corn by the time I get into my blind. I might as well turn my regular feeders off when I start spreading corn with the wheeler as the last thing they touch is the corn under the feeders. I do not put out too much corn, just “blip” the feeder every two or three wheeler lengths to encourage plenty of movement. I also “blip” the feeder anytime I see a deer while riding (the wheeler) so the deer associate it and corn. I also park at the ladder to my blind.