I just tried this out and it's very nice and easy to use. Thank you for sharing!
I ended up copy-pasting the output from the messages page, which is 99% of the way to exporting a .txt file and my personal use case. Great work.
What do you typically do with the text on export? E.g. Do you parse the times?
1) You can add more timestamps by adding paragraphs with enter.
2) You can playback at any word by highlighting it and pressing space. You can also cut with right click on the wav ui.