Darkstar, I didn't say accidents, but accident rate. It has been shown to be higher with self feeders. Chuck and ducks scare people into being cautious, self feeders lull you to being careless.
For years, I had the best hand fed chipper ever made, IMO, the Mitts and Merrill. Still made and sold by Karl Kuemmerling, it has a different design than all other hand feds. Due to the position of the bed knife, and the 12 staggered knives,the feed rate is much slower, and the chip quality was better than my Bandit 250, especially with small and stringy material.
The only drawbacks were the non full swivel chute, 8 inch capacity, and longer knife change procedure. No hydraulics, and only 3500 lb were a big plus...