When working with the Form Libraries in DocuSign, a specific form can only be added to the Room once. This is by design for how DocuSign Rooms work. The form added into the room is considered to be a working copy of the form and will be used for any edits made to the form for any number of recipients.
Let's say that a specific Room has two recipients, who must each be sent a customized version of that form. Within the Room you would open the form and edit it with the details for Recipient 1, then place that edited form into an Envelope and send it to Recipient 1.
Then, the Library Form that is still in the Room can be blanked out and filled out again for Recipient 2, with new details (this will not affect the Envelope that was created for Recipient 1). Once the form has been filled out for Recipient 2, it can be placed in a new Envelope and sent to Recipient 2.
Once Recipient 1 and 2 have signed their respective forms, DocuSign will then place a unique signed version of the form from each of the Envelopes into the Room.