Yes, we use this function in XStore theme files. Additional customization is outside of our support https://themeforest.net/page/item_support_policy so unfortunately, I can’t help you with additional customization. But you can submit customization request here to get a quote if you need help with that.
If you plan to do customization by yourself don’t forget to use the child theme for these purposes, and don’t make changes in parent theme files.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.