What problem does this address?

We currently have a bold indicator when dragging/dropping blocks within the editor, but in the List view, it is quite thin/not as easily distinguishable.

What is your proposed solution?

1. Let's try a more consistent drop indicator here that also improves visibility of the indicator — perhaps 1.5 or even 2px wide. Perhaps even matching the focus state width (in the last screenshot).

2. As an extra, perhaps lean into matching a corresponding animation (perhaps not as bold as the editor itself, but relative to the List view size) for the line indicator as it appears.

Current drop indicator within the editor:

Current drop indicator within List view: