I have also really been missing this feature. Very handy when you want to jump to a specific time in an instant replay or similar. Also the ability to see how long there is left of a video would be really nice. This is a must in professional productions, if you are playing back videos you'll want to know when that video is done playing for timing purposes.
I would like to say that OBS is a great piece of software and i really love it. Really appreciate the work you devs are doing :)