The Hub client is awesome and work smooth, but could be better.. in my case would like to add custom buttons or pages inside, like documentation, or promotional links/banners, things like that, single stories that will help the resellers that use hub client.
For example, wants to create a promotion to offer the same services wpmu have like emails, the products and services or even the expert services, then would like to be able to create a single button to lead to a single page where are the products available (just like wpmu does inside the hub)
Also, wants to create a helps page for my clients inside the hub client, to include my custom documentation for the reselling services or to show the videos of the plugin Integrated Video Tutorials.
Things like these doesn’t require much effort or long planning for wpmu team but wil be pretty usefull.