Is a client workstation installation Required for the Document Creator Designer?

For users of the Microsoft Dynamics NAV Windows client:
No, Document Creator in completely integrated in NAV. With an Editor license, the Document Creator designer can be started from any Windows client. This also guarantees that the report designer and report execution are using the same DCR version.

For users of a Dynamics 365 Business Central client:
You can download and install the Document Creator stand-alone report designer to edit layouts. Please find more on the Installing the Designer page of the Installation Manual.