How to use `unknown` in Typescript overloaded function implementation signature

What is wrong with this overload signature? My goal is to use overloaded signatures to create several type-safe versions of an permissively-typed API. The API takes a string channel parameter and a handler callback with an event first parameter and then whatever parameters you want (event, ...args[]) => void.

It seems to me that string can be assigned to unknown, so the overload argument (event: Event, msg: string) => void should work with the implementation argument (event: Event, ...args: unknown[]) => void

function handle(
    channel: string,
    listener: (event: Event, ...args: any[]) => any
): void { }


export function typedIpcHandle( // ← Works great
    channel: "getVersion",
    listener: (event: Event) => string
): void;
export function typedIpcHandle( // ← 💥 Error
    channel: "notifyUser",
    listener: (event: Event, msg: string) => void
): void;
export function typedIpcHandle(
    channel: string,
    listener: (
        event: Event, 
        ...args: unknown[] // ← any[] works, but unknown[] doesn't
    ) => unknown
): void {
    return handle(channel, listener);
}

The second overload signature gives this error: This overload signature is not compatible with its implementation signature.(2394)

This is IPC Handle in Electron, if that is helpful.

Typescript Playground