All the warning message is telling you is that those edits won't be visible when you're using the tool. They will still show up on the timeline and when you produce the final video.
I'm unclear on what the function of a mask is, but as long as it's position is tied to the full clip it shouldn't be affected by the C/Z/P tool - however that might not be the case when using the PiP Designer or KF tool.
In other words, you need to be careful about making changes to the clip independently of an applied mask and you may actually need to produce the clip and mask to permanently "fuse" them before you can apply the zoom keyframes using the Keyframe tool or PiP Designer.
If you don't want to use the C/Z/P tool for the zooming keyframes, the process is nearly identical in the KF tool or PiP Designer to what my video shows except you'll need individual keyframes for each changed parameter.
Start by placing matching Scale and Position keyframes with the clip centered and full screen. For your timing examples, add a pair at times 0:00.00, 0:17.00, 0:19.01, 1:21.00, etc.
Assuming you don't want the smooth zoom I showed in the demo video and instead want an instant jump to the zoomed area, place a new pair of Position & Scale keyframes at 0:17.01 and change the scale & position as desired. You may need to zoom in on the timeline scale to place adjacent keyframes so close together.
Once you have the zoom and position set, go to 0:19.00 and choose Duplicate Previous keyframe for both the P and S settings. This will retain your zoomed view without changes from 0:17.01 while the previously placed pair of keyframes at 0:19.01 will snap back out to the full screen view.
Again, the initial placement of the full screen keyframes and the setting and duplication of the zoomed keyframes for each section are identical to what I showed using the C/Z/P tool. The main difference is that you have to do it twice as many times because you need one set for each parameter you change.
Also if you need to pan the zoomed window to follow the dancer's movements you may need to play with the ease-in/ease-out tools on the Position settings to give you smooth motion.
The main advantage of using the PiP Designer/Keyframe tool is that you have full control over every aspect of keyframing, but at the cost of having to explicitly set every parameter you want to change. The C/Z/P tool doesn't give you anywhere near that level of control, but it's typically much simpler and quicker to use.
This message was edited 2 times. Last update was at Jun 17. 2021 16:20