Removes the last caveat. The Benfei (Prolific PL2303) on the bench is physically the cable from the failed office setup, not a substitute picked up later. The chain has no inference left: that cable is a PL2303; the Micromate USB host has no Prolific driver in either firmware line; a laptop on the same cable and modem round-trips perfectly; the Micromate on it never answered. The FTDI cable arriving 2026-09-26 is now a confirmation rather than a test. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Ru8Lg9HkkYvX9VWWo65SmL