Deadline date separate of the end date

When planning a piece of work I have two data pieces I would like to manage independently:

- when I want to do the work (a start and end date) and
- when the customer needs the result at the latest (the deadline)

The deadline isn't the end date.

I'm struggling to have that reflected in Wrike properly.

I know I can have milestones in a project, but those force the begin and end times of the project to be around the milestone. Also it would be desirable for the deadline to be displayed in the same line in the timeline chart:

Really it would be great if the information "when will I work on this" and "when does it need to be done" is separate but in the same line and visible even if collapsed.

Or is there already a better way to do this?

Jens Theisen VisBricks