The Stable channel has been updated to 73.0.3683.88 (Platform version: 11647.104.0/1/2/3) for most Chrome OS devices. This build contains a number of bug fixes and security updates. page
I tested access to the Chrome OS Downloads folder that I previously shared with Linux and observe that I can now access the folder, open, and edit files from Linux terminal. Therefore, this release appears to resolve the issue that I observed in Chrome OS Version 72.0.3626.122.
I have found that file/directory sharing is available to all containers and not just penguin. Consequently, I can access the Chrome OS Downloads folder in penguin and fjmdocker.
This release also expands directory sharing to Google Play and Drive. AboutChromebooks