How does one merge takes in Character Animator 2020? That is not an option that appears available to me.
I don't think you can merge them. You can layer then one on top of the other, you can blend the start and end to transition, but you cannot merge them. You can collapse the view so it takes up less space, that is about it.
Japanese to English with translation software.
What's new in version 3.4
You can combine multiple lip-sync takes into one track.
Merge takes makes the timeline easier to see.
A simple sample was uploaded to YouTube.