DS is working in France for a year, we live in NI. He flew home via Dublin (drove down & collected him before latest restrictions) and due to return after Christmas same way, to go back to work. Now with no permitted air travel between U.K. & France or U.K. & Ireland, however afaik flights continue between Ireland & France. Also border open between NI & ROI. Can he travel down & fly back via Dublin even tho been in U.K.? (On Irish passport if that's relevant)?