I have no suggestions since we took the regular bumpers out, and the breathable bumpers won't be much help...we go in and frequently move LO away from the edge of the crib if he's migrated there. And if he bumps his head and cries, then we move him and he goes right back to sleep. I really don't think there's anything you can do, but I don't think it's going to hurt LO to occasionally bump into the slats
Re: Bruises on head from crib...