Hi John thanks for posting in the Lucid community - I'm happy to help!
This supplemental metadata is not included within the pre-written script provided by the SQL Server export option. Any additional information you'd like to include beyond the attributes within the script will need to be added to the "Create" statements manually including data types indices and foreign keys where applicable.
I certainly understand how it would be powerful for the export tool to automatically include this information within the script however and we're always looking for ways to improve Lucidchart. If you're willing to share would you please add your thoughts and use case details to our feature request form? Ideas submitted here are considered by our development team when prioritizing improvements to Lucidchart. Thanks for your request and apologies for any inconvenience.