A tourist asks a local for directions to Dublin. The Irishman replies: ‘Well sir, if I were you, I wouldn’t start from here’. (Apology: this old joke has also been told about a Scotsman, a New Yorker and probably others, so no disrespect intended to the Irish in particular.) 
If you wanted an invisible, frictionless trade border between the UK and Ireland the best place to start would be where we are now with free trade and common regulatory standards. The EU has unilaterally decided that we cannot travel anywhere, or that Northern Ireland at least must stay in the Customs Union to avoid a Hard Border with customs checkpoints. It would also need to stay in the Single Market, in effect if not in name (‘full alignment’), and be subject to decisions of the European Court of Justice. The Province would have no say in any of this, it would be ruled by Brussels and Dublin, a clear win for the IRA/Sinn Fein.
Which is worse a Hard Border or a Hard War? What would be the likely response of the UVF? Might it take up arms again and wouldn’t the IRA then respond? This is a ruthless, dangerous and despicable strategy of the EU, choosing to put the ‘integrity’ of its treaties ahead of peace and fair compromise. Meanwhile they blame the other side, the UK Government, for jeopardising the Good Friday Agreement.
The EU is making a big issue of a small problem. Northern Ireland’s trade with the EU is tiny, a fraction of one percent of its total trade. Smuggling across the border has always occurred but again it’s such a little problem that nobody has cared very much. It is a ploy to retain control over the whole UK as far as possible.
When it suits the EU is quite able to compromise, fudge or look for alternative solutions to problems. The common currency experience is full of examples of forbidden bailouts, illegal trade surpluses and budget deficits and just about anything to keep the show on the road. When it doesn’t suit, the EU is blind to compromise and entreaty.
The USA/Canada border is mostly invisible. Replicating that requires investment and a willingness of both sides to act like they are friends who wish to trade. The EU has looked into technological border controls and concludes it’s possible (see Smart Border report).
Boris Johnson illustrated the use of technology to check consignments crossing borders by reference to the London congestion charge which automatically checks whether vehicles crossing into the zone have paid the charge. 
Naturally the EU and hostile Remainers ridiculed him for his simplistic suggestion. Of course Boris did not say, or even imply, that this simple example would meet the needs of a complex customs frontier but made his point in a way that anyone could understand. We too described how lorries and containers today cross borders without physical checks, displaying the TIR plates most motorway users will have noticed (see Snippets 1). Essentially trusted and formally registered traders do their “paperwork” electronically before departure and on arrival. New methods are constantly being developed and block-chain technology (which is behind Bitcoin and other crypto-currencies) is another likely contender because of its ability to securely track every recorded detail of a journey – number plate cameras or whatever.
However, the Irish border has always been a bit leaky in practice but nobody has been too worried. Besides, not all taxes are the same in Ireland and the UK, like VAT for example. A willingness to cooperate is all that’s necessary even if some ‘transitional period’ is required to implement solutions for the trickier parts. A blanket refusal to put pragmatism before purity of the treaties in this case is further proof of the EU’s malign and anti-democratic intentions. The EU plans to continue its rule over the UK despite the peoples’ decision to leave. Or failing that it seeks to divide the UK. This is dangerous and imperialistic.
We are astonished that well-informed Remainers are helping our adversaries to impose upon us. Some have seen through the bluster: 
“I voted Remain. I can see some advantages in a customs union. But I will not be bullied by an arrogant Commission conspiring with opposition parties to undermine the elected UK government and the integrity of our Union. Back in your box, @MichelBarnier” – Nick Boles MP on Twitter
This EU Won't Work 