One big flaw I raised with the EU authorita's in 2015 was that it has no provision for displaced nationals. I raised that several times, serveral MEP's from many countries, Tusk, you name it.
The response - nada, nothing, zilch and even too this day, not one single MEP or eurocrat has bothered to fix that glaring flaw that sees and allows innocent nationals to be used as negotiation pawns.
Even now, no attempts are being made or driven to fix this oversight in Article 50 and that kind of lack of priority and care is never going to win votes in the public's eye's. So it could all happen again, causing undue and unfair stress upon innocent people caught up in a situation that could of been totally avoided.