In my study, I have met a lot videos whose subtitle timeline is wrong, and its translation timeline is also wrong.
For me and most non-English speaksers (I think there is a lot), it’s hard for us to learn the video only by sound. Without subtitles, we can’t learn well and it’s so annoying. Even for some of them, they can’t continue learning until you fix it.
I know it’s huge work for you to rectify every timeline, but if you develop the function, we can adjust timeline ourselves. Those who cannot listen English well don’t need to wait until you fix the vidoe’s subtitle timeline.
I think it’s helpful for Coursera. And I hope Coursera will become better and better in the future, I have learnt a lot here. Thank you! 
There is a option to join the global community for coursera translation I advice you to join that and contribute, GTC so that others it helps others with their learning.
Thanks,
Khushwanth