Better way to extract all the details from SAP BO instead of calling each object with ID?

My requirement is to extract all the metadata from SAP BO.

The process I followed is Get all universes, then get each universe with its details. Get all folders, then get each folder with its details. The process continues for documents, reports, report variables.

For example if we say we have 1000 objects (inclusion of universes, folders, documents, reports, variables), then we will have to make 1000 API requests to SAP BO to fetch the details. The number mentioned is just a minimum, this number can go upto multi-millions. In such a case we have to call SAP BO multi-million times to get the details. And this process is too slow and takes a lot of time to complete.

We use Java.

Is there any other better way to extract the data or any recommendations to use SAP BO APIs efficiently?

Any direction here would be helpful.