Delayed rendering splits monitoring into two problems the article treats as one, so push on it. A monitor that only reads formats on WM_CLIPBOARDUPDATE sees the publication and never the request, so a policy that blocks by content is inspecting whatever the owner chose to put there. Provenance helps. Does it survive an owner that renders late from a protected window into an unprotected one, or does the attribution end up pointing at the publisher and missing the paste entirely? Have the audit record answer that before anyone trusts it.