Weirdly, this should be a common issue, and i still can't find any discussion on it:
Using "Split Media Here" (cmd-shift-X) on a video track will cut it in two pieces at the playhead.
doing the same on a nested Timeline which has multiple subtracks will not actually "split" this timeline. It trims the left side and the right side gets reset to its starting frame.
so when i cut a timeline that's 4:00 long at 2:00, i end up with two identical pieces running from 0:00-2:00.
Isn't that unusable? feels like a bug to me, how would I insert a pause on a nested timeline, for example?