There is a link on the Xara website that talks about the March 2019 Release https://www.xara.com/us/web-designer/whats-new/. For completeness, here is the link to the v16 Release Notes; the contents page shows March 2019 updates (to the original v16 release notes) http://releasenotes.xara.hosting/web-designer-16/.

Would be useful if these links were in the Xara Help dropdown menu (and they opened in a separate window).