I suppose you can use the Act as taxpayer function within the Intuit Link drawer of your client's return.  I believe PTO will still register those as importable tax documents so long as you have the correct document type chosen.  But I haven't tried whether this works if clients declined the invitation.

My thinking is that it's not worth your time unless there are a lot of details from these tax documents that can't be input as summary entries (with or without an attachments for support).  Otherwise, it's usually more expedient to manually key in the entries yourself.