How to Change backup time:

Cpremote use scheduler option to schedule the backups. You can change the time of each schedule from the WHM page

How to speed up ssh or sftp uploads:

The openssh service by default only accept 10 concurrent connection from an IP . So if you are using parallel backup option , sometimes the ssh/sftp connection will be slow. This is not an issue with cpremote . To increase the speed , you need to configure the remote ssh storage pool server settings as follows,

Edit /etc/ssh/sshd_config and add the following lines

    
       MaxSessions 100 
       UseDNS no
    

Now restart  the following services

    
      systemctl restart  sshd
      systemctl restart  systemd-logind 
    

You can monitor the ssh log files in /var/log/auth.log or /var/log/secure to see the connection traffic.