Windows Server version 1709 brings the following important improvements that developers can take advantage of with the updated container images.
First of all, the microsoft/windowsservercore image underneath SQL shrunk by more than 2GB, so the SQL Server images are also 2GB smaller.
The networking support for containers was improved to support Kubernetes, now at beta in version 1.9 beta on Windows, and routing mesh with Docker Swarm.
If you want to store your databases on remote storage, you can now by using global SMB mounts (New-SMBGlobalMapping) along with a docker volume (docker run -v c:\shared:c:\data microsoft/mssql-express-…).
Seems like a useful improvement.