A QuickPlace has documents for which the field h_IsPublished = "".
Notes Migrator for Sharepoint automatically only selects published QuickPlace documents. In other words it has h_IsPublished = "1" hard-coded in.
A notes Developer could write a simple agent to set the value of h_IsPublished = "1". The migration could then be performed, after it was completed
the value of h_IsPublished would have to be set back to "".
Enhancement request ST61192 has been submitted to Development for consideration in a future release of Notes Migrator for SharePoint.