The host's one toast for a hardware controller that moved but is not mapped: the source and channel, a live value, a chip you drag straight onto a control, Pick control (click or arrow keys and Enter) and Ignore. It never takes focus, fades after the control goes quiet, and guides any source-first pick. Every edit goes through the shared CC drag controller, so drops into sandboxed face frames work too.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-cc-unmapped-notice.json"