I made a very similar suggestion 2 months ago in this thread:
The response from Dan was “No”.
I also had made a request about a “zoom fit” button that could be placed here:
It would function as a zoom that would instantly adjust the view of the timeline to cover everything from start to end so that one could get a quick view of everything in the project in one view.
However, there is a main issue with the timeline which is when it gets over a certain length (about an hour) the speed of the zoom starts to slow down considerably. I suppose that would have to be improved upon first before anything else and who knows when that will happen as Dan has a lot on his development plate.