Once you start building more complex sitemaps, you may want to disable certain parts of your sitemap for testing and debugging purposes.
For example, you may want to test some changes to the early (_root) part of your sitemap, but you have other selectors (such as Click Link, Click More, Click Element) further down the graph that need a long time to load and which you do not need to test.
One obvious solution is to just delete the elements you don't want to test. But you would then have to re-create them later and also deal with reordering them within the graph.
To temporarily disable selectors, I just rename them, usually by adding "XXX" in front. WS will "fail gracefully" when it cannot find the selectors and just fill in Null for the data scrapers. Later on, I can just remove the XXX to restore the selector.