I would like to know if it's possible to change some default system value with a child theme.
For example, if I go to
Configuration > Catalog > Product Review > Allow Guests to Write Reviews.
The default value seams to be
Yes when the checkbox
use system value is checked.
I would like to know if I can override the default value from a child theme using XML config file, so guest are not allowed to write reviews by default and should be enabled manually from configuration if needed (by unchecking
use system value).