Beyond this specific product, whether a seller offers live chat or email-only support is worth checking as a general responsiveness indicator.
Live chat support generally suggests a more actively staffed support operation, while email-only support may mean longer response times — a general pattern worth checking for any seller.
Sending a test question through whatever contact method is available, before you place a larger order, gives you a real sense of response time rather than assuming based on which contact options are listed.