Right, so it's an opt. The general recommendation (or at least, my general recommendation) is to set the opts of all child resources to be the opts of the parent resources, unless you know better. As the docs you linked say, ComponentResource doesn't honour this, but you explicitly set the child opts this way, then each of the children will have the custom timeout.
Which unfortunately means you could end up waiting (custom timeout x number of child resources) for everything to time out... but that's why I said "unless you know better" 🙂