Before your first shipment, test their support by asking a semi-complex customs question (e.g., “Do I need an FDA prior notice for ceramic mugs with wooden lids?”). If they answer clearly within 24 hours, they’ll likely manage your routine shipments fine.
You need proactive problem-solving, ship dangerous goods, or require warehousing/fulfillment integration. Look at Flexport or a local forwarder instead. flehippo