Next workspace not visible in overview at high resolutions/100% scaling
At very high resolutions (past 4K, e.g. 5K, 6K) and 100% scaling, when there is a single in-use workspace, the edge of the next workspace isn't visible in the overview.
It seems like this is because the overview apparently relies on the other UI elements (search box/dash/workspace thumbnails) to reduce the size of the main workspace previews, and at high resolutions, they don't occupy a high enough percentage of the height of the overview.
When a second workspace is in use, the edges of the next/previous workspaces become visible in the overview, at least at up to 6K resolution, as the workspace thumbnail section causes the main workspace previews to shrink sufficiently, but presumably at a higher resolution the same problem would occur.
An upper limit on the percentage height (or width) of the main workspace previews should fix this, to avoid relying on the other UI elements occupying a sufficient percentage of the overview height to guarantee next/previous workspace visibility.