And yet, there's a "hidden feature" that does exactly this. If I place markers in the source sequence, they show up in the nested sequence. So it's easy to match the two. Here's what I mean:
First, in my source sequence, I place a couple of markers using the "m" key:
Then, when I look at my nested sequence (in this case, my multi-edit sequence) I see markers in the timeline that I didn't explicitly place there, that correspond exactly to the markers I placed in the source sequence:
Is that cool or what? Saves me a lot of time and frustration. Those Adobe engineers... pretty good code, PPro cs6 is. Pretty darn good.