This is why I see that --no-zip doesn’t work in the right way, is not useful that Plesk use a switch like --no-zip and the destination direc
Plesk 12 on Windows
Actually, pleskbackup utility uses a flag named --no-zip where files into the destination compressed folder are not previously compressed, but Windows OS read the .zip extension of the folder like a compressed file and this increase so much the backup time (this because become a great I/O consumption).
I think this is not much useful, the correct behavior should be that when a --no-zip switch is used, the destination is not a ZIP file but a standard directory!
In case of servers where many domains with thousands of little files, use a "normal copy" instead of compressed folder like is now, can be really usefull to complete a backup in less than 24 hours.
Another issue can be to configure the Backup directory and not have a "hardcoded %plesk_data%\Backup" directory, but ask to sys admin to decide where the backup is pointing (for example, on an external SAN, external device and so on)
Unfortunately, we have to close your request, because over the years it has not become quite popular for further implementation.