That primitive method fixed the transfer of title and ownership as irrevocably done. Signatures on paper later came to replace this earlier method as marking the event. Electronic signatures can replace ink ones for this purpose, but the signature is a step in a process extrinsic to it, and the process is not a property of the signature. By court rule or in California by statute, submitting the document is the act which fixes the intent. I don't think so.
Intent is expressed by pressing a button to upload a document, but there is no signature.
Another method of establishing intent has been used and is either implicit in the application or if more information is needed, this should be reflected in the document, not as a Signature Property. I agree that at some point a line should be drawn and respected as to what is a property of the signature and what is not.