Chapter 8: Dynamically Rendering the Template Using Template Macros

1. JSON. It is either a piece of a template or a full template, depending on whether the Transform section is declared or the Fn::Transform function is being used.
2. No, because a macro and its function must be in the same Region.
3. The stack operation will be considered as Failed and CloudFormation will start rolling back.
4. Yes, but you need to be aware of the macro evaluation order (https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-macros.html#template-macros-use).