Just a quick look exposes few quirks/leftovers, i.e.:

• the page template definition uses a sitemapType property of no use (default renderable definition, null value)
• from an UX perspective it might be good to give the radio control for switching between desktop/mobile variations at least some title (and/or description)
• missing values for i18n keys like dialog.pages.googleSitemapProperties.
• missing update task