I believe Nostr clients shouldn't use the Nostr protocol for DMs, rather something like SimpleX embedded in the Nostr Client itself (if possible).
Much more private and secure conversation.
cc: nostr:npub1xtscya34g58tk0z605fvr788k263gsu6cy9x0mhnm87echrgufzsevkk5s nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z nostr:npub1jlrs53pkdfjnts29kveljul2sm0actt6n8dxrrzqcersttvcuv3qdjynqn