Jerry Lucas in his blog explains that when a notary identifies a person who requested a notarial act (the requester) by means of a credible witness, the notary should have the credible witness complete an affidavit attesting to the identity of the requester. The sample provided by Mr. Lucas includes statements that the requester lacks acceptable identity documents, and that the affidavit is attached to the document that the requester is having notarized.
I've looked at the Colorado Notary Handbook (March 2019), at the version suggested by the Uniform Law Commission, and Vermont's version. None of these require that the requester lack acceptable identity documents. That is an idea that comes from California. The commentary in the Uniform Law Commission version indicates the reason for the provision is to accommodate requesters who lack identity documents, but it is not an actual requirement in the law.
An instance, often discussed in internet notary forums, is a person who has an identity document in one form, for example, a driver license in a maiden name, and needs to sign a document in a different name (for example a married name, when the person just got married an hour ago). The credible witness might refuse to swear the person has acceptable identity documents; the person does have an acceptable identity document, it just isn't in the name the requester want's to use.
The other issue is attaching the credible witness affidavit to the document the requester is getting notarized. I don't believe this is correct. The notary does not attach identity evidence to the requester's document. The notary wouldn't attach a copy of the requester's driver license, nor a photo of the requester and the notary when they were together when they were both ten years old, so it would be equally inappropriate to attach the credible witness affidavit. Instead, the notary should retain the affidavit in his or her records in case the notarization is ever questioned.