Tuning cPanel backup

Hi, We'd like to use cPanel backups server-wide (for servers with hundreds of accounts) but we encounter one problem. The server generates the individual account backups much faster than it is able to offload it to our off-site NAS (some 6MiB/s; the servers have SSDs in hw raid 10 so they are somewhat fast). The resulting problem is that the server gets full to the point where we no longer have any spare space which will obviously wreak havoc on a busy cPanel server (and probably to the backup process itself). We are trying to get a faster network to the NAS but this is not the actual issue so faster network is not the proper solution. Networks can be fast but they also can have a bad day (the un-commited ones). Even worse: the network can be down for a time. We need to do this for multiple servers and to be able to leave the backup process unattended indefinitely without the fear that we'll end up with 100% utilization on "/". Is there some option to setup the backup in a serial manner: package the first backup, upload it, package the next backup, upload it and so on? I believe the legacy backup worked this way but the old backup has a very rudimentary (and quite inept IMO) way of managing the backup retention. The new one seems better in this regard (though not perfect). So...is there some way to tune aspects of the new cPanel backup to do it in a "serial" fashion? Thanks, Regards!