Hi
I agree. It's annoying actually, as pulling up the white bars to reduce the preview window will not expand multiple tracks to fill the space made available as it does with a single track. It just widens the "Drag and Drop your Video here " bar. 🙁 I am sure it would be quite possible to always expand tracks to fill that wasted space.
Best option currently is to monitor the tracks using the Sequence preview screen making it as large as possible.
Nat