I use Hovabators, and I put the eggs in directly, without a container, because they just don't have any head room for containers. I've used them both with the base filled with moist vermiculite, and with the water tray filled, and fluorescent light grid over it, for substrateless. I've been using substrateless exclusively this year, as the eggs seem to do better, and I don't have to clean vermiculite out of the hatchlings' noses, lol.

With the Little Giant, the primary issue is that it doesn't seal as well when you close it. If you tape it closed, and cover the seams, it should fix that humidity problem. (You will have to undo it to open the incubator, but you shouldn't have to do that more than once every couple of weeks anyhow).

My local feed store had one, and I rejected it for that reason, but with some sealing, it should work.