What is the productive way of doing multiple speed changes in a video editing project?
Your screenshot does not have sufficient zoom to see how the checkpoints of Velocity envelope behave. Let me assume they are all having Transition of Hold, e.g. velocity changes abruptly, not gradually: 100% immediately to 150%, then immediately back to 100%.

Along the course of my experience with Vegas, I found velocity envelope inefficient. Instead, I find splitting Video Event into several ones more effective, and here's why.

Say, you have a video event of length 1 minute, as on Track 1. Say, you want the original timeline 0:20 till 0:30 to play at Velocity of 200%, so that it took only 5 seconds instead of 10 original.


Full scale image here

If you add a Velocity envelope as in Track 2 (200% at timecode 0:20), you would need to guess at which point to put another control point for Velocity so that playback continued at original speed.

Also, the end marker of the video indicates that the actual timeline ends at approx. 0:54 (and the rest is a repeat of the same video event from the beginning).



However, if you take another approach and split your video as displayed on Track 3 and then Ctrl+drag the end point of the middle Event, it would work smoothly. You will be sure that the third Event starts at proper timecode (in original scale).

The only thing you would need is dragging the 3rd Event backwards, as shown in Track 4.

Moreover. As soon as you Group all three Events by Ctrl+clicking them and then pressing G, you will be able to process them together. In Track 5, I have stretched all three events so the entire video played a bit slower.



Note 1. Most likely, you will need to overlap these three Events somehow. This will let the stream to be smoother, without abrupt Velocity changes.

Note 2. Of course, all above applies to multi-track Groups as well. You need not keep all Events within the same Track.