One clip in four cards at 1/8, 1/4, 1/2 and full resolution. It decodes once and is drawn into each card, so all four always show the same frame. Drag Final onto Draft and switch to Difference: only the detail the draft lost lights up.
pnpm dlx shadcn@latest add "https://keyframeui.com/r/sync-grid-render-demo.json"