When using dynamic references, you can now have CloudFormation use the latest version of an SSM parameter whenever you create or update a stack. You are no longer required to specify a specific version.
StackSets now supports creating or updating stack sets with self-managed permissions from templates that reference macros. For more information about macros, see Using AWS CloudFormation macros to perform custom processing on templates.
You can now use a period as a delimiter in specifying the fully-qualified logical name for a resource contained in a module. For more information, see Referencing resources in a module.