Did you save a ‘Book’ with the customized report?
I keep a placeholder Person of surname “Gramps” to anchor Notes containing customization, “SuperTool Script”. Media attachments can include report_options.xml, books.xml and custom_filters.xml files or other items that are omitted from backups. Archival clones of those items can be transcribed to Notes when it becomes necessary to reduce clutter.
This allows those ‘omissions’ to be included with backups that include media. Note that you might have to connect the placeholder person to your core tree so that they are not filtered out in an export. Making them Private probably is not an option since that filters that person out of many exports.