Yes I'm fully aware how that works.
And that's why I'm baffled, the only alternative has been offered by the EU and was rejected, it was also a solution that respected the fact that NI voted to remain. As long as NI choose to stay with the UK and the UK rejects any option that would divide the Union, there is no solution that the EU can offer. The other solution only concerns the Republic of Ireland, they can decide to join the UK in a new block.