AE should be allowed supervised visitation. That's what happens often to parents in the UK who behave the way she does. As for giving her 50/50 custody, IG would frankly be a fool at this stage to go for that. As you said, AE won't change, therefore the PA would be non-stop unless he gets 100% custody. AE is not a normal mother and should not be treated as if she is. A normal mother wouldn't be under a restraining order for starters. That simply enables all her narc behaviours and the PA.I dont really think that this is how it should go, long term, anyway. Alice is their mom too. We must not do the same mistake as her and her psychos and act like one parent deserves to be erased. I definitely think joint custody should be still the target, but of course Alice wont ever change, so this whole thing is all easier said than done.
Go for 100% custody IG!