How does Interactive Brokers deliver the bitcoin to you? When I looked up the instrument description, it says: Settlement Method Physical Delivery Physical Delivery Not permitted at Interactive Brokers
IB will not allow the physical delivery to happen (Just like what they do with commodities), there will be a cut-off date for longs and shorts where you will need to close out your position before, otherwise IB will auto-close the position for you to avoid physical delivery. Search for BAKKT on this page to know the cut-off dates/times of different contracts. https://www.interactivebrokers.com/en/index.php?f=deliveryExerciseActions&p=physical
BTC from CME volume is quite decent. margin requirement $74K / lot! BAKKT Bitcoin Futures @ ICE is quite low. Bitcoin Cash settled monthly Futures from ICE Futures Sgp volume - you need to use a microscope in order to see it.