when i had egg eating probs years ago i created a dished area in 3/4 pine board so the eggs rolled to the middle, then i routed out a center hole large enough for eggs to fall thru. I cut the board to fit my nesting boxes, put spacers under the boards to hold them off the bottom of nest box a little more than the height of an egg, and when turned so depression was upright and placed in nest box with a thin cussion material below the hole, the eggs roll thru the hole and are protected, it worked well. If this sounds like a solution for anyone, i could make those depressiond boards to fit your nesting box for a cost of $8.00 each. To collect eggs you just lift the board. no need for straw, wood chips or any other nesting material. The hens never seemed to mind sitting over the hole. An additional benefit is that eggs don't accumulate accessably so hens have nothing to go broody over..
You got pics?