what really gets me is the lack of communication and poor documentation on error messages.  Still have no clue on what the 571 is for.  seems to be a 'something went wrong and we have no clue' message.  that leaves their support team in a terrible place.  in the meantime we're reading tea leaves.

I have no doubt shopify is partially responsible for the lack of progress here.  you call their support folks and they feign ignorance.  it's an INTERFACE.  there are two ends to it.  BOTH parties have support obligations here.