With a custom site map generator, like I use, updating site maps several times per day is not hard at all. I typically update around 200 pages per day, and often update the site maps 5 or more times per day. Easy peasy with the correct site map generator.
By the way, If you site built up in word press then you can use yoast SEO plugin. Other create file through XML file generator and fix it in back end server.