nice work!

Can we have a fallback to the value which we had before? Otherwise we might break existing users which had the event name as a string. e.g. at the end of the on overloads in the Page.

    @typing.overload
    def on(
        self,
        event: str,
        f: typing.Callable[..., typing.Union[typing.Awaitable[None], None]],
    ) -> None:
        return super().on(event=event, f=f)

Can we have a fallback to the value which we had before? Otherwise we might break existing users which had the event name as a string. e.g. at the end of the on overloads in the Page.

    @typing.overload
    def on(
        self,
        event: str,
        f: typing.Callable[..., typing.Union[typing.Awaitable[None], None]],
    ) -> None:
        return super().on(event=event, f=f)

This is non-breaking change moreover it is typing only change hence there is no runtime change