the workflow Designer does not consume a license.
If you want to log in to DW to test a newly created configuration, yes, you need a license. You can either assign a license to the admin user, use another user instead of admin for testing, have at least one concurrent user license or switch named licenses around via administration any time you want to test things.
Those are just the 4 ways of going around that problem which came across my mind now, maybe there are more.
I hope this helps.
Greetings from Germany,
Simon H. Hellmann
DocuWare System Consultant