@functions {
    ElementRef statDiv;
    string status = "";

    void HandleEvent(MyEvent e) {
         status = e.time; // updates every second
         StateHasChanged(); // renders MonstrouslyDeepApp--every second!
    }
}

@{
    Also_do_monstrous_business_calculations(42);
}

<div class="main">
    <div class="main-toolbar">
        <span class="flex-grow" ref="statDiv"> @status </span>
        <span class="oi oi-cog"></span>
    </div>

    <CascadingValue Value="@ModelRoot" Name="M">
        <MonstrouslyDeepApp M="@ModelRoot" />
    </CascadingValue>
</div>