What I've done this year with the substrateless is gotten a container, tilted it on it's side and hot-glued a support underneath to keep it at an angle. I've filled the lower half with those shiney decorative pebble things, filled with water, and then placed the light crate over the pebbles, so that it is level while the container is still tilted...if that makes sense.
This way, I'm hoping any condensation that forms on top of the lid will just run straight down, and since I've filled half the container with pebbles, I don't have to worry about the eggs tumbling/sliding away.