Creating a mapping for designated signer

We have customers who are using forms that do not always require one specific role to sign or have information populate (Informant is not always Primary Purchaser) and would like the versatility of 2.0 to pull the information based off of signer, rather than the role. Having a mapping for things like "Signer Address" or "Signer Email" would eliminate having to type in information that already exists in Family and Friends and can easily be auto-populated.