It would be great to have it so that I can specify that a particular signer is optional.
I have have a document that needs a student to sign the document and one other person. Frequently, the student is under 18 and needs a parents signature, so I need to have the parent sign before the other signer. Right now, I have to determine if the parent is signing before I generate the cosigners list and depending on the number of signers, select different documents (which causes me to have to maintain more then one) with the same but slightly different details. With this requested change, I could specify which signer the person in the list is signing as and therefore if the signer for the parent signature was not in the list then it would not be sent/required during the document signing flows.
Maintaining documents (especially when they are identical except for a single signing field) is tedious as the editor is less then idea for managing the functionality. Hopefully I am wrong, but the only way I know to prepare a document is through Adobe Pro's editor.