I just received my Oskar's treasure chest + jewel from Meffert's. It's a pretty cool concept... though I found a flaw: you don't have to solve the entire puzzle to open the box, just the top two layers. Is this intentional, or was it an oversight?
I proved this by doing a 3-corner cycle on the bottom layer, and it still opened no problem. Same with a 3-edge cycle. Upon closer inspection, it's obvious that locking mechanism is only keyed to the top two layers.
Here's a challenge for you geniuses out there: can you modify/extend the existing mechanism so that it does
depend on all 3 layers?