By cabinet I mean the big back end boxes that contain the transformers and power electronics, not the charging posts. The V4 charging posts are taller and have long cables but that doesn't make the installation fully V4. The back end cabinets will list the max voltage, if it's 500V then they are V3, if it's 1000V then V4. Have you looked at the labels, do they say 500V or 1000V? I would expect that the transition to full V4 should happen soon because the Cybertruck is finally shipping and the Cybertruck is 800V.