Looking pretty good, just had a couple questions. I'm wondering if there's a way to abstract out blocks like this:

title?.let {
    setTitle(it)
} ?: run {
    titleRes?.let {
        setTitle(it)
    }
}

I'm guessing there is, just wondering how to do it and make it understandable.

I couldn't figure out a better native way with scope functions, so I created a "quartus" extension function to simplify this, let me know your thoughts about it.

private fun <T, U> Any.quartus(
    primaryValue: T?,
    primaryAction: ((T) -> Unit)? = null,
    secondaryValue: U?,
    secondaryAction: ((U) -> Unit)? = null
) {
    primaryValue?.let {
        primaryAction?.invoke(it)
    } ?: run {
        secondaryValue?.let {
            secondaryAction?.invoke(it)
        }
    }
}