I used a perlite vermiculite mixture for years, it works fine. The problem I had was needing to add water once in a while, or to just mix it up. The water seemed to move from the center to the edges of the container. With hundreds of eggs it took time.
With the substrateless method, there is no guessing what freshly dug earth is like. Just pour some water in the bottom, it doesn't matter how much, as long as the water doesn't cover the egg crate.
The only work involved is cutting the egg crate, I did that once many years ago and re use it over and over. I don't even change the medium below the egg crate.
Don't get me wrong, I'm not trying to get anyone to change their method, if you are happy and get good results that is all that matters.
The perlite seemed to allow a little bit of air flow in the substrate.
Ball eggs are so easy to hatch it doesn't hardly matter what you do.