Amontillado wrote:

That's a good thing. The encryption is handled by the OS using OS
features heavily used and constantly refined. Meanwhile, Devonthink
accesses an encrypted file exactly the same way it would access an
unencrypted database. Files are still kept in their original form. They
are in an encrypted box, rather than being encrypted or modified in any
risky way.

This is what I assumed was being done with Obsidian. Perhaps they'll eventually get it working.