Yeah it ended up that it was my brain and I just needed to wait 0 as the second object had just been created. However, the issue with the editor not suggesting relevant expressions after adding the IID is a thing. Not sure if it is by design but I can't see the benefit if it was.
You type "object." and are presented with a list that only contains valid expressions related to that object.
You type "object(0)." and and aren't presented with any valid expressions.
Just a UX issue.