With the smaller version of that type feeder that I have, there is practically no waste. Before I got that, the pigs turned over their feeder, crows and other birds were waiting on me to feed the pigs and there was lots of waste. Not to mention feeding them twice a day. It is MUCH easier to just fill it up as needed. You will soon be patting yourself on the back for being so brilliant as to make your own feeder of this type.
You have it secured with a bungee strap. I made a framework of 2x4's screwed together, so I can take it apart. It is screwed to the wall. So far they have not destroyed it.