Currently my client does not generate their financial statements from OneStream, however, is looking at using OneStream as a tool to possibly import, edit and publish into an adobe design template or word document for their Annual Financial Statements so that they can update comments and numbers and then export from OneStream again (basically trying to remove the back and forth to type setters') does that functionality exist in OneStream?
I think I am missing something in your question. Is your question if OneStream can import (trial balance) data to publish their financial statements based on this data in a Word file or as PDF, and, then possibly adjusting the numbers in OneStream (as per data model) and then publish their financial statement again?
If your question is more with regards to editing the financial statement in Word (narrative reporting), you might want to have a look at the OneStream Reference and Design Guide's section on extensible documents (E.g. see chapter "Presenting Data With Extensible Documents"). One can also use this functionality in conjunction with Task Manager (if I am not mistaken) and check out different chapters of a document and steer the collaboration process with this solution.