Issue Plesk Backup with Small Disk Sizes

[mdde]

Hi,
I have some Questions please:
How can i improve the Plesk Backup to FTP?

1. If Backups are created, I think I need double disk size in order to have no fails, is that correct? If so, can I improve that by turning off compression on backups?
2. If I want to restore some single database out from server backup, it pulls the whole backup to my VM, this requires me to have a huge disk.
Can I prevent that by turning off compression? Will it then only pull less data temporarily to origin server?

I looked at docs and didn't find the answers to my questions.

Thank you in advance.