Can AWS CloudFormation be used to deploy new/additional workloads, based on that initial CF template? Much like a golden image.
Yes, you can. When you create resources using CF, AWS create a "stack" that centralize all resources created with the CF template.
When using the CDK of AWS. You can have a current version of your architecture deployed and you can redeploy a new version using the command, "cdk deploy". AWS will automatically make a diff between the existing stack and the new stack from your CF template. This, it will deploy only the change.