I have obtained the ID of a Managed Folder and used it to obtain a handle on the Folder using the REST API. However, I am wondering if the ID is guaranteed to be unique across all projects in Dataiku - this will help determine if I need to call get_managed_folder() from the project rather than the top-level API client.
Folder ids are indeed unique across all projects. However, the DSS API can only access a folder within the context of a given project. Hence, you still need to specify the project key, as documented in: https://doc.dataiku.com/dss/latest/python-api/managed_folders.html#dataiku.core.managed_folder.Folder