Currently, on JSPUI, the admin user is able to export metadata from "simple search" and certain "browse by" pages, the results will include the filtering the user is performing on that specific search.
And with that metadata results in the CSV format, the user can do metadata batch editing.
That Export feature it's also available in CLI (but only for communities, collections, items or all) - https://wiki.duraspace.org/display/DSDOC6x/Batch+Metadata+Editing#BatchMetadataEditing-ExportFunction.
My suggestion it's to extend that feature to be able to also export related items.
[dspace]/bin/dspace metadata-export -f name_of_file.csv -i 1023/24 --relation isAuthorOfPublication