Hey there,
I have created a simple custom Inspector for DialogueNodes (without the children because I was not able to display that correctly sadly).
Here you can see I can choose Predicate based on my Enums:
Here you can see when I choose different Predicate I get different options.
Here I can see all the quests and choose one:
Here I can see all InventoryItems and choose one:
Its not really efficient but since its in Inspector its not really a problem. Also if someone knew how to make the List of children please do write down below
PS: Im also working now to make it type safe (at least a bit)