Are spirit imprints actually cordings and thought forms from spirits? Do they really need to be included as a separate phenomenon in the protocols, or can that request to address them be removed?

You have figured this out intuitively, the seeming mystery of what spirits might be doing to the being who is victimized in this way. It is just their own cordings and psychic attacks that result from the encounter, in some cases long-term attachment, where they can do much damage to impart false beliefs and many kinds of propaganda that has a malicious intention and may create looping thoughts visited over and over and over again, as well as the more serious delusions exhibited by those mentally unbalanced. Those, too, are originating as cordings and thought forms deposited within cellular memory of the mind, primarily. It is useful to have this discrete step in place because the cordings from spirit meddlers, who have no standing, can be removed summarily with little difficulty by the divine realm and that creates some efficiency in the order of battle in doing a healing session and its replicates. So this is good to maintain as well, for teaching purposes in how spirits cause harm and the metaphysical mechanisms utilized.