Pedro Lopes gives a reason to upgrade to SSMS 17.2:
But what if I could search for node id 30 while looking at the graphical showplan?
Starting with SSMS 17.2, just use CTRL+F to start a search in graphical showplan (or right-click on a blank area of the plan, and in the context menu click on Find Node option), and you can quickly see exactly where node id 30 is:
I will have to see whether that also lets you quickly find the origin of Expr#### columns.