It is okay.
Just for info, custom CSS can be added in few different places:
1/ Theme Options -> Theme Custom CSS -> Global CSS (saved in database)
2/ Customizer (Theme Options) -> Additional CSS (saved in database)
3/ xstore-child/style.css (saved in file)
The difference of our Theme Custom CSS and Additional CSS is in the fact that if you want to import/export settings then Theme Custom CSS will be included in the export file but Additional CSS won’t be because it is in the separate tables in database and not included by default on export.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.