Maybe I was a bit blunt but there’s a lot going on here, far more than two parents who have split amicably and want to ci-parent.
And it’s you asking for advice on having the DC more, how motivated actually is he? I think what I’m trying to get at is that you are quite vulnerable in this relationship. Do you know if his attends Narcotics Anonymous and if not, what therapy has he had so far? What’s he said about NA? Has he ever had any other addictions like gambling or drink? Does he have any other DC?
As for his ex not revealing their address, was there any DV involved? No matter what’s been said about his previous relationship, I would for a a Claire’s Law request, just to rule it out.
I’m pleased that the DC are back with their DM and see their DF regularly but they have had huge trauma in their lives already and this whole situation is going to require very careful handling, on everyone’s part.
Does he use a shared parenting app already to communicate with his Ex? If not maybe you could suggest to him
to have a look at one of the Court approved ones like OurFamilyWizard.
These apps have benefits for both parents and help to maintain a constructive relationship between the Parents.
Do you know of there is a Child Arrangements Order in place? If not, maybe ask him why not? If there is one and the Mum isn’t sticking to her side does he know why? Are the DC struggling a lot with being back with their Mum? Would she be ok with him having the DC for a little longer, so maybe asking for the contact to be extended by one hour for a few weeks at first to see how the DC cope?
Has he been in touch with the school so that he receives communications from them about things like Parent’s Evenings, School Reports and Nativity Plays?