As I said above,
"I would try a very small shot of spray glue between sheet layers.
Just a mist of Duro All-Purpose Spray Adhesive." @Local hardware stores.
In the directions, they say to spray 'one surface', so you can re-posistion.
If you spray Both surfaces, it's an Instant bond. Faster than super glue!
Anyways, the idea being, use very-very little adhesive. One molecule thick if possible..
That should give you the best possible coro-to-coro contact.
I've put off cutting my coroplas, since I've been so dang busy with car-recall, medical, dental, basement repairs, & FiOs problems..
Now, I just might wait to see how your DIY OFC (One Foot Cube) works out,
before I start hacking my little 8" Cube..