You might be "on your own" in the tree dried stakes Javaphile.
The Yemen is as close to tree dried that I have gone and it is only partly tree dried. It is SHG SHB (high and hard) coffee that expands very little in the roast.
It sounds like your beans have a rubber more than brittle quality (not taste) that is stopping the crack..... hmmm... did they have a higher moisture level?
Maybe the long contact with the drying fruit softens the hardening bean (more sugar transfer maybe!)
Yes, I would be interested to try tree dried one day.
Ill keep my eyes peeled. ::)