Had a reply; the official process is posting the Cheque to - Customer Operations, Monzo, 230 City Road, London. EC1V 2QY. clearing is 5 days and a note with an email address is required.
As an idea; could we not still take a photo to assist in the process (may/ may not speed up). Then when the technology is there for photo processing it would have been apart of the function before? Plus with the photo element, this would tie up who the cheque came from (should they not send an email address) a notification can be send via the chat feature?