How do I set EchoSign for Sharepoint web part to only sync documents that have been sent from the same site?

Since EchoSign for Sharepoint (the web part) is basically worthless with any site over 2500 documents, we have broken up our sites so that the web part can successfully traverse the site without timing out. However, within the web part, there is an option (two green arrows) to synch with SharePoint. Unfortunately, users can sync any document from EchoSign to a SharePoint library. I dont want the users synching documents that dont belong in that library. Are there any settings or coding that will allow only the syncing, or actually auto sync the documents, to within the same site?