You'll have less snails if you don't overfeed, and ramshorns don't eat plants, they will eat dead plant material. If you have holes in your plants, sounds more like a mineral deficiency.
That's what I thought too, and I cut back on feeding after removing 2 sandwhich bags of these snails. Then after a week of careful feeding, in the am turning lights on, the ramshorns were covering my soft leaved lotus that was in fine condition at lights out the night before and when they all left, the plant was rittled with holes and tears. I figured they were eating the plants because they were unable to find food. I am very diligent about feeding slowly so that the fish are able to eat up everything before it hits the substrate. I watch the feeding like a hawk. The Angels and Betta are fed by hand after the Puntius Denisonii feed. Since the lotus I pick these things out of my tank everytime I see one no matter what I was about to do at the time. They have put holes in a few other plants too...maybe there is a difficiency somewhere, but the only time I find new holes is in the morning after the snails fed for the night.