'Squash' a timeline so that it uses the minimum number of tracks
Often while editing it's necessary to use a lot of tracks that are useful during editing, but later unnecessary and messy with lots of clips high placed high in the track ordering and lots of empty space below them. This can be cleaned up by selecting clips on the timeline and moving them down in the track order until they are positioned on a track that has a clip below it. There may be for example a clip on track 7, and no clips on tracks 6,5,4,3 or 2 and 1 clip on track 1. In that example, there only needs to be 2 tracks on the timeline.
With only 2 clips, a manual fix makes the most sense, however on a timeline of many clips, there may be a lot instances where the tracks can be 'squashed' down. A button to 'squash' the timeline, would be helpful to do the careful manual work of moving clips down one by one in a single click with no damage to the timeline.
This would be most useful especailly when creating multi camera source sequences of multiple clips in a bin at once, which currently places each synchronised clip in to it's own track. For myself, most of my multicamera work is just 2 cameras and so I would only need two video tracks in the resulting multi-camera sequence. If I could squash the timeline, it would save me moving down each of the clips so that the timeline is only two tracks high. This feature would be useful on finished edited timelines as well as a final cleanup. In such cases the feature would need to account for effects that are dependent on absolute rather than relative track ordering.
James Clark commented
Antoine Autokroma: Indeed you can, it's what I currently do. The point is it's something that could be automated to a single click and without too many considerations or complexities that I can think of. I suggest it as a feature for the same reason that 'delete empty tracks' is already a feature. You could raise the height of each and every empty track on a timeline and right-click and press delete until there are no empty tracks, but Adobe saw the usefulness of a one-click approach to this.
This feature, if implemented would essentially be a variation of the 'delete empty tracks function' in as much as it would be automatically eliminating unused spaces on tracks, without destructively affecting the arrangement of the timeline (no clips deleted).
Now that you mention it though, it would also be good if the feature could optionally 'squash' and then also if desired, delete the empty tracks as well. I don't know if it was clear in my original post, but in my example of a clip on track 7 and another on track 1, simply deleting empty tracks would already work as there'd be only 2 clips, but the difficulty that this feature would hopefully solve would be if there were more clips on any of the tracks 6,5,3,2 or 2, later on down the timeline, this would make sense for a form of 'checkerboarding' to organise footage, but sometimes you want to clear that up later. It may be that once cleaned up, it was only necessary to have 3 or maybe 4 tracks if all clips were vertically flush, hence 'squashed', with all empty vertical space between them removed.
Antoine Autokroma.com (Independent Developer of AfterCodecs, BRAW Studio, PlumePack, Influx) commented
Yeah. Maybe you can do that manually and delete the empty video tracks ?