adding on to this, would be good to have the option to bill based on estimates rather than actual time spent on tasks. This is how our billing model works, because it's not always the case that I want to bill the client the time actually spent on a task from various reasons (e.g. we have minimum billing blocks, some tasks take longer than they should because of internal errors or because the person assigned it learning so they take longer than they should). Having the ability to bill on estimates would solve all of this.

I too would like to estimate time for deliverables (and set a default value for when an estimate is not provided). Going a step further, it would also be very cool to see total of estimated hours in the Kanban on each card and a total under each column.

Possibly include a "time chop tool" or Gantt chart to show how long a project/deliverable will take, how many hours I need to plan for, when I will work those hours, and a way to mark the hours or deliverables as completed.