EU referendum, brexit and the aftermath

Indeed. As far as I can see, the argument goes as follows;

1. We have to leave the customs union.
   
2. Therefore we have to have a border, not least due to WTO rules.
   
3. We can't have a border between EIRE and UK due the GFA.
   
4. We can't have a border between GB and NI because DUP and 'no UK PM could ever agree to that'.
   
5. Therefore, there being no other place to have a border, we can't have a border.
   
6. We can't avoid a border without remaining in the customs union.
   
7. Goto 1.
   
   

It all seems very simple to me that there is no way out of this. The ERG want to wave magic 'technology' dust over everything to make the problem go away, but for these purposes 'technology' seems to me synonymous with 'cake' or 'unicorn'.