Brexit/Ireland conundrum

In a short table.  Caveat:  Declan Gaffney tells me Ireland are not ok with turning a blind eye to smuggling people and things, as indicated below.

The argument for the Y is that it allows Ireland a de facto frictionless border, even if not one in law.   Declan's point is that the smuggling funds end up in the hands of former terrorists.  At least that is what I read into his tweet.