Bug 39848 fixed the issue where users without edit_catalogue permission can delete the record if no items remain from the batch item deletion. We and some others (https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=39848#c7) however have need where we do want staff to be able to delete records when no items remain during batch deletion. Can there be a new permission to allow record deletions the record if no items remain from the batch item deletion? Edit_catalog (per manual): importing records through z39.50/SRU, and duplicating records), edit existing bibliographic records, merge existing bibliographic records, and delete bibliographic records New permission (maybe no_items_delete_record?): remove record if no items remain. I also know that a button can appear when manually (not batch) removing items and the last item has appeared -- something like 'No more items remain. Delete Record?'. Maybe we could have that permission turned on with this permission too since it does the same thing as the checkbox when batch deleting.
Please take a look at bug 35953. The second patch covers this issue and allows patrons with suggested new permission delete_bibliographic_records and items_batchdel permission to delete biblio record if no items remain.