I appreciate that everything seems amiable now and that’s great. But the problem is that after a split, people’s feelings and / or circumstances can change very quickly.
Men, especially single dads, often meet a new partner very quickly. Sometimes then they want to have their kids 50:50, so they don’t have to pay child support and they have another woman to care for their kids.
And of course they pay less child support anyway if she has kids.
Others go the opposite way and decide to not see their kids anymore , or at least not have them overnight, because it’s too hard in a blended family.
Or they decide to move aboard and want their equity out the house.
Now I know you are reading this @Wideawakeandcountingsheep and thinking that your STBX will NEVER do that because he loves his kids so much. And that you are smarter than all those other women that happened to, who were clearly idiots who married a bastard.
I’m afraid that they all thought that too. No one marries and has kids with someone they think will do this in future. But sadly many many of us do.
So I’m saying that you can’t rely on his promises here. Get everything done legally and try to get as much of a clean break as possible.