And if we keep both borders open, then we don’t have a hard border with the EU which is one of the central reasons for many brexit folks in the first place.
Wrong. You are forgetting the part where there already is, and will continue to be for the foreseeable future, a hard border between Ireland and Schengen.
It wouldn't take much political finagling to completely fuck up the current status quo. Worst case scenario for the Leave faction would be if during one of May's intermediary Brexit periods, the UK is "temporarily" entered into the Schengen Area. The ROI have thus far stayed out of the Schengen Area because joining it without the UK would force the UK to impose a hard border between NI & ROI, which has a high risk of breaking the peace, and at the very least pissing everyone off. If the ROI joined the Schengen Area after the UK "temporarily" joined, this would put the UK in a difficult spot, and one our government would use to justify canceling Brexit - though they wouldn't describe as such, insisting we'd left the EU despite being further integrated into the EU. Temporary would become permanent, everyone would be salty with no crispiness, which is a recipe demanding spice.
This is the current arrangement:
Green = Common Travel Area
Blue = Schengen Area
Grey = Dudes who use borders when their governments exist
Green area mandems have minimal border checks with each other, but cooperate to maintain border checks with blue.
Blue area mandems have minimal border checks with each other, but cooperate to maintain border checks with green and grey.
Also green area dudes can permanently live in each other's countries, serve in each other's armed forces, governments, bureaucracies, private sectors and all that without needing any visa, residency or naturalisation.
Blue area dudes can permanently live in each other's countries, work in each other's private sectors without visa/residency/naturalisation, though public sector eligibility requirements still vary from nation to nation on a bilateral basis.
Wasn’t aware of that, but most of what I’ve seen in terms of the NI border was customs related rather than immigration related. Is it not in the customs union?
UK & ROI are both in the customs union, while the UK government still to this day hasn't made it clear whether it will leave or remain in the customs union.
Everyone said we'd leave it,
The UK government promised to leave it, insists it will leave it, and yet spend every day concocting plans to lock us in. The communist party of Britain, which I did not realise still existed, called it amusingly when they said the
Chequers plan was the single market by another name.