Thanks for asking.
You can use staging in licence manager to validate test environment and test updates before doing the same on live website.
You can get more information on our product validation article:
I would also encourage you to take a look at following resources to update Cornerstone and X Theme:
Version compatibility guide: To learn about the latest and compatible versions of bundled and supported plugins, please take a look at following doc:
2. Theme Update guide: Please take a look at following article to update Cornerstone.
3. Please take a look at following doc about changelog: