Thanks bauerdog, especially for posting the picture. I have 28 in the tray, with one rail down the middle, set this morning. Tuesday I'm picking up 6 eggs to incubate for a friend.
Thought I'd pull out my least valuable homegrown eggs and stack 6 on the top for the first week until I pull...
I'll see if I can find a picture of what I did in one layer- I used a few cardboard spacers here and there.
Don't think I'd stack them, no way to secure them.
Looks like I did use one rail and a foam strip down the middle:
I got 29 eggs in once by staggering them in one layer without using the rails. As I pulled the quitters, I did have to re-arrange and use some rails. Not sure I would stack them, but worth a try.