In Disk Usage allow to also include network attached volumes and/or other mount points - not just "/"

We have clients using spanel where they have large disk requirements. For them we deploy a network volume and mount it, then symlink it under their account. 

It'd be nice to know what the disk usage for those is without having to SSH and run commands on the console. If disk usage allowed us to include network attached volumes also that would be super handy. 

Similarly, if we could have quotas enforced on those volumes also it would be great.