A lady got 17 Buff Rock Eggs from a Master Breeder shipped to Arizona he used my method which I was shocked as he don't send eggs but has the best strain in the USA.
She hatched I think seven or nine chicks and they look fantastic. In fact she will be a supplier in years to come of this rare color of Plymouth Rocks. I think you could use your method of putting the eggs in bubble wrap up and down and then pack them tightly with shavings or more bubble wrap. You got to keep the eggs tight and they cant move around. The decoy in this madness is the box. They think their is live birds in this box so the box is hand carried from point a to point B to your house. They also are kept in the live section of the Air Plane with Fed Ex and not in a bin with other two day priority mail. My sources at Fed Ex tell me these are all old converted Passenger Jets so the Pressure and the Temps in this jet is just like the cabin for the pilots.
When you are shipping rare hard to get eggs you need to make sure they have a shot of making it. The only other method I have had good luck shipping eggs is UPS ground and they are better at handling the eggs than the post office. In fact I hate to put Hatching Eggs on the box with the post office it seems they treat them worse than if it has nothing on the box.
On the Thermostat I think I am going to order me one. Do you think they would work well in a 1201 Game Bird Box Incubator from Georgia Quail Factor? I got to get a new one and the replacement for that unit is $80.
I use the STC-1000 on everything from a Farm Innovators Styrobator to a wine box to my incubator in the Philippines that can easily hold 600 eggs. Its got a built in relay that can handle 500 watts easily. It should work on just about anything.
I think the box is the key as well. As far as packing goes - I am moving towards pipe insulation cut into 6 inch lengths. Its cheap and effective.
When I am carrying eggs in my golf bag, I will still use the foam inserts as I can get 72 eggs in a box and about 260 in the bag.