That and the post-Brexit situation completely f***ing up large parts of the NI economy (although of course, such a f***-up would inflict considerable collateral damage on the parts of the RoI economy that actually do things other than play around with tax leverage).
Those are connected, as if there is a Norway-style deal little will change from the perspective of the RoI and little for Scotland either and a good portion of the Scottish leave vote would accept that (fishing and farming communities seem to be a big element behind it) and perhaps Scotland would stay in the UK, oh God knows how the kippers would react - it would be such an obvious stitch-up (I say 'little' would change as I believe there are still some EFTA-EU compliance issues for certain goods even within the EEA). 'Brexit Max' otoh with full barriers and tariffs though would be extremely bad and it is hard to see how NI would cope or how Scotland could handle it. The nightmare scenario is an Independent Scotland in the single market and England and Wales outside it, meaning trade barriers on the border of England and Scotland and between Northern Ireland and Scotland. Presumably to connect with their own country ferries from NI would to arrive in Liverpool as opposed to Stranraer or Troon (or is there any ports further north in England than that, could Barrow play this role?)
"Brexit Max" just seems a very bad idea in very many ways. Unfortunately
the lunatics are in control of the asylum.