I know I am going to regret asking this but you said "It(UK) suggested there should be no border posts ... but that a mix of technology and physical checks..."

Where are those physical checks carried out? A temporary border post put in place for a day many have worked before the era of mobile phones, but as a means of ensuring smuggling is not going on it is fair to describe it as 'fantasy'.

And pointing out the proposed approach would not work is not to say I want a hard border: I don't.