First eggs - but hen wants to drop them on plywood

We are currently 3/4 on egg yield - one was cracked on the end, I suspect because she keeps kicking out all the nesting material in the center of the nest, thus exposing the plywood bottom. She did this first with pine shavings that had a golf ball. Then I tried no golf ball, but refilled shavings - she kicked those out too. Then I tried straw. She kicked all straw out of two boxes and in the third, pushed it out from the center and laid an egg there.

Do most people line the bottom with something soft? I worry it would be hard to keep clean, but also don't want to risk a cracked open egg getting eaten.

I'm going to make the front lip a bit higher to make it harder to kick stuff out, but she may still just push it out from the center leaving a nice hard wooden target to drop the egg on.

Thanks for any other ideas...

-Colin