You forget that this is Schroedingers Brexit. The one where we both take back complete control of our borders (and the Brexiteers cheer) and leave a border entirely open (and the Brexiteers cheer).
You can't expect these fucking idiots to hold a solid and coherent thought in brains that have the consistency of wet porridge. The Ireland problem has been clear and plain since the minute that the vote to leave was made. Nobody has ever squared that particular circle, because it can't be done. So instead you have a border in the Irish Sea, that Boris tried to pretend wasn't going to be there, and all the issues that ends up causing.
Mark my words, these morons running our country will end up breaking the GFA if it gives them a 1% boost in the polls compared to carrying on with the current situation. They have no morals, no shame and by and large no clue.