Passport decision

Hi all in need of urgent opinions or views (if you've been in the situation that helps too)

So to give a bit of background I separated with my sons father last year due to years of DVO
He refused to sign for my sons passport last year as I wanted to go home to see me dying grandfather.
Fast forward a year later and I send my ex the papers to appear in court to sign the papers or let the court grant it without.
He suddenly shows up in my town saying he's changed and he just wants to be friends for our sons sake so he can be a father and see him more and that he will sign the passport if I give him a months notice I said what was wrong with having 2 weeks notice like I stated in the court order he told me that he may want to spend some time with our son before I take him overseas for the month.
I said to him how do I trust that if you sign the passport papers and the passport goes ahead that you won't put a stop to our son leaving the country by applying at the borders.
He is aware of the hauge convention,
He seems like he's a changed man, but part of me is saying be weary.
My family have said go ahead and let him sign the passport, as my surviving grandparent is hanging out for us to come home.

Should I trust him that after he's signed for the passport that he won't put a stop at the border?help!!!