There is an important cPanel exception to backup exclusions: the global and local backup-exclude files do not control the contents of a Home Directory partial backup created from cPanel's Backup interface.
They apply to the supported account-backup processes documented by cPanel, including the Download a Full Website Backup workflow, but not to the Home Directory partial-backup download.
If you need a smaller Home Directory archive, do not assume cpbackup-exclude.conf will remove those files from that partial backup.
