Hi Mark

Thanks for posting in the Community!

While it is possible to modify Smart Containers it is not possible to modify their shapes.

You can modify the grouping field (container name) add new smart containers containing different shape data to your document move shapes from one container to another move smart containers adjust the column number in wrapping containers and shapes add additional fields to shapes within smart containers add a custom field and apply default styles to smart containers.

You can learn how to do all this in the following help article: Modify Smart Containers

Please note that smart containers are automatically sized equally which means all containers will match the size of the largest group. There is not currently a way to resize smart containers.

We're always looking for ways to improve Lucidchart and your feedback is the best way for us to do that. Would you mind adding your idea to our Product Feedback section? Ideas submitted are passed on to the product development team for their consideration. As a growing company we take our feature requests very seriously. We are continuously looking for how we can make our product more useful and effective for our users and we pass that information directly to our product development team.

Thanks for your feedback!