Raising them up certainly can help reduce wastage. It also keeps them from scratching bedding or other trash from the run in there. I'm not sure how high that is. It kind of looks high enough.
Another trick is not so much wire mesh but bars across there so the chicken cannot swing its head sideways. That stops the billing out. The head needs to be able to fit between the bars. The spacing for the bars will probably change as they grow.
If they are actually getting in there and scratching, which they will if they can, the bars can stop that too.
As a matter of trivia, in hatcheries where they house hens and roosters together to get fertile eggs but want to feed them a different diet, they put the rooster's tray feeders up pretty high, well above the height of their back, so the hens can't reach up there. To keep the roosters out of the hens feed, the bars are spaced so the hen's head can fit between them but the space is too tight for the rooster's head. The point of that is to watch the bar spacing so the chick's heads can get through and not get stuck.