Would be nice to see in the dashboard how much disk space each site is using.
With that also when creating a site (and ability to change later on) to limit the maximum amount of storage space and optional database size a site is allowed to use. (with hard limit or soft limit) hard limit: no files can be uploaded anymore soft limit: just a mail notification/notice in the dashboard but everything keeps working.
Would be great when having multiple client sites on a server, bonus points for including the disk usage data in the flywp plugin and show the usage in the dashboard for the wp-user