How to use Kotlin Android extensions with ViewStub?

Question

Do extensions have magic to trigger a bloated performance? As far as I can see, I have to break the harmony of the code and causefindViewById

The goal was to inflate the layout layout_ongoingViewat some point and again make it hidden and visible depending on the scenario

<ViewStub
    android:id="@+id/viewStubOngoing"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inflatedId="@+id/ongoingView"
    android:layout="@layout/layout_ongoingView" />

And codes

override fun hideOngoingPanel() {
    if (viewStubOngoing !is ViewStub) {
        findViewById(R.id.ongoingView).visibility = View.GONE
    }
}

override fun showOngoingPanel() {
    if (viewStubOngoing !is ViewStub) {
        findViewById(R.id.ongoingView).visibility = View.VISIBLE
    } else {
        viewStubOngoing.inflate()
    }
}