[PapaBear3625]

The hard border controls violate the good Friday agreement. Commercial border controls are grey but are a potential solution. Long term, I think your option 3 makes the most sense

I would add, that if you are NOT an Irish citizen, and go into Northern Ireland, you need a visa. There might not be hard border controls, but if you are stopped by police (with profiling being a legitimate cause for a stop) and are an illegal alien, you go straight to jail.

Thereafter you might find yourself forcibly deported to a destination of UK's choice. Possibly left on the beach in Libya.

[Cronos]

note - if you go to Ireland, you need a separate Irish visa. Ireland is’t part of the Schengen zone.

So the UK would then send the pick-ups in NI back to the RoI