Hello ipcom
Thank you so much for contacting us!
The best way to customize a theme is to do your customization in child theme that is why we have specially designed a child theme with the theme package.
As for theme update is concerned Please note that If you have done some custom changes in CSS or any other PHP files then only those changes will be lost after updating the theme, So we will recommend you kindly take backup of your existing theme and then update your theme.
Robert Hall















