Dragging off the grab tile previously reverted the cursor to default, since §7.9 resolves the shape by hit-testing the pointer position. That is the CSS-behavior-correct rule, so the fix lives in userland, not the spec: while held, the demo appends a capture-mode floating overlay that declares grabbing across the viewport. The shield wins the hit test everywhere, freezing hover beneath it exactly like browsers freeze :hover during a drag, and disappears on release. Verified headlessly through the real parser and renderer: grab → grabbing on press, no change dragging to the far corner, default on release in empty space, state clean after.