The border is a consequence of a botched vote come about by Tory arrogance, though. Cameron was convinced that nobody would vote to leave the EU so didn’t put in any caveats about different parts of the UK voting for different things.
Scotland and NI both voted to stay, which really should have stopped Brexit before it even happened, but the “equal partnership” only works when the partners vote with England.
As for Stormont, The unionists don’t want a border with the UK, trade or otherwise, and the Republicans don’t want a border with the rest of Ireland (the island, not the country :p) but neither of them can really get that after Brexit. Currently the Republicans get the benefit of that because politicians domestic, continental, and globa are all terribly aware of the return of terrorism should the GF/BA fall to bits.
Currently there are more members elected to that body that are in favour of the NI Protocol in its original form than against it, so the DUP should really drop the D from their name because democracy is not at the top of their list, but given the unionist position essentially being summed up in this quote, emphasis mine:
Jim Allister, leader of Traditional Unionist Voice (TUV) said the agreement "does not live up to the overselling spin which accompanied it".
"As for it being enough to cause unionists to give up its Stormont leverage and settle for this deal, which comes with the added packaging of a Sinn Fein First Minister, then, no thanks," he said.
I am also not surprised.
Edit: forgot a link to the
article the quote comes from.