I've done a quick screen record hoping to make it a little clearer! What I want to do is only add velocity to the split clip, then be able to split it again (as I usually do using that black triangle thing), thus syncing it back up to the next bit? But it is using the full length off the video to end the velocity section with the black triangle.

Thanks again!

I'm not sure why there is a need to split the video event to apply a velocity change. Why not apply the velocity envelope to the entire video event and use nodes (double click at the desired point on the velocity line) to change the velocity rate.

In the above, the velocity rate is 100%, then 0%, then 200%, then 300%, then back to 100% - and no notches created. R clicking on a node opens a context window providing velocity rate selections and includes a manually selectable % velocity rate:

I'm not sure what you mean by "syncing" (which usually refers to audio/video alignment???) - the uploaded video does not that make clear.

@SeldomSeen I understand what you want.

1.Select the event where you will apply the velocity envelope.
2.Right click and choose Create Subclip
3.Again right mouse button / Switch / Trim events to include all frames
4.After that apply velocity envelope

Notwithstanding, I have several times in the last few months using Vegas Pro 20 (and over the years in other VP versions using a number of earlier computers) been able to split a video event after one frame, 0% freeze that one frame and then stretch it out to, say, 2 seconds and then butt it up to the 100% continuation of that same video event after the split point - all without the need to create a subclip and without the frozen velocity event affecting the following 100% continuation of the same video event after the split point, and without creating the end of event notch (black triangle???). I do this to create a freeze frame at the beginning of the video event mostly to cover a dissolve and then release it to 100% velocity at the split point.

Sorry to say but the 2 uploaded video examples have not illuminated my understanding of what is being done as they are without a commentary - jiggling the curser over a later video event unfortunately explains nothing for me.