It's perfect! On some other custom-coded XF forums where I'm a member, I've seen this feature.
I've been looking for an add-on, since I'm not a coder and am not in a position to hire one for my fledgling forum. I even asked another add-on developer about it (but he didn't see a demand for it).
Then just last night I found yours! It's exactly what I wanted. Worth the money!
In a long thread, a you (the user) might want to filter it down to just the posts by a particular member (or even your own), if you're trying to find a particular post... or if you want to get a sequenced "summary" of a member's thoughts on the topic. I find it quite useful.
Highly recommended, folks!