When the duplicate list is edited currently the revision history just lists the post IDs of the duplicate list before and after the change:
Can those post IDs be actual links to those questions?
Pretty much anyone that is ever evaluating such a change is going to want to actually go to one of those questions, which currently would mean constructing the URL themselves.
If the lists could show the actual title as well, just like the actual close dialog, that'd be nicer still, but just having the question IDs be links would be good enough for most purposes.