Out of the Protocol, Into... what?

 Ulster Unionist Party MLA Steve Aiken said: 

"Anyone who has a grasp of the provisions of the Belfast (Good Friday) Agreement will note that the principle of consent is fundamental and that at the very least the protocol does not have the consent of the Unionist and pro-Union population". (BBC News)

But how is consent necessary for the Northern Ireland Protocol, but not for Brexit itself, or even for the decision that the UK should leave the Single Market? 

Surely if consent is a requirement for the arrangements to avoid a hard border, it should be necessary for the decision that a border was required in the first place - the decision that the UK would not only leave the EU, but also leave the Single Market?  

Since the majority in NI voted not to leave the EU, how can anyone claim there is consent in Northern Ireland to additionally leave the Single Market (which during the referendum campaign we were told was a separate issue)? And if there is no consent for extra borders, how can the UUP argue that consent is somehow required for how those borders work?

And even if "consent" were remotely relevant - how do the Northern Ireland Protocol's opponents think NI/GB and NI/Ireland trade should work? It seems to me that if you're going to argue for change, you should at the very least explain what changes you think would better protect both free trade with Northern Ireland, and the EU's Single Market? To be fair, the UUP have some proposals for improving how trade works (and they had seemed more interested in making it work, than in abolishing the protocol). But the DUP and TUV don't appear to have any solution beyond a nice hard border between Northern Irelend and the South, and exporting GB's petrol shortages to NI.

I can understand (if not excuse) a failure to think Brexit through. But if Brexit has taught us nothing, it surely shows that we should think rather carefully before trying to swap the NI Protcol for some vague promises that things could be better - some day, somehow. 

I get that Unionist politicians want out of the NI Protocol frying pan. But where exactly do they think we'll end up if we follow them?