A developer has a single pre-production AWS account that runs an AWS SAM CloudFormation stack. They edited a Lambda function and added SNS topics and want to do a one-time deploy of these changes for testing without impacting the existing pre-production application used by the release pipeline. What should the developer do?

Deploying to a separate development account is the best practice for testing changes without affecting the pre-production environment. This isolates the new features, ensuring the existing application remains stable for the release pipeline. Using the AWS SAM CLI to package and deploy to a dedicated development account provides a clean, isolated testing ground. Deploying directly to pre-production with a debug parameter risks unintended side effects. Creating a change set in pre-production and executing it elsewhere is illogical; change sets apply to the account they're created in. Updating the pre-production CloudFormation stack to point to another account is an unnecessary and complex way to achieve environment separation.