There are two profiles in the Products.CMFPlacefulWorfklow add-on. The changelog says that the "base" profile was created for version 1.5.4 in 2011, with "no dependencies on the default Plone types to allow use in an archetype free dexterity environment". Does that still apply?
Also, installing it with the portal_quickinstaller tool installs which profile, base or default?
Likely (why should it have changed?)
I would expect it to install the profile default (however, I am not sure. I remember to have recently read a detailed description about the behaviour of portal_quickinstaller, likely even here. Maybe, you try to find it).
However, I assume that you will not use the configuration in the profile default. Instead, you will likely make your own profile with your own configuration which likely depends on the profile base of CMFPlacefulWorkflow. Then there is no need to install CMFPlacefulWorkflow via portal_quickinstaller; instead, you install your extension, wich installs CMFPlacefulWorkflow as a dependency.