When you buy a email template on market you have to use module email manager of Prestashop to set configures and manager email template but it only allow you change available configures that email template support, If you want to custom other text that don't have configures you have to use function Translation email on Back Office and it work normally but when you go back use save configuration of module email manager of Prestashop the text you just changed will be reset to default because data translation will be replace on your change. Besides when you buy new template and you want to install new template but you don't want to lost old configuration of old template but when you change to new template you don't like that and want to use old template but you don't mind old configuration and you have to need more time to set configuration for old template.

As an email template developer we see this inconveniences so we develop that module to help you process that problem.