Dev Mode is enabled using the filter fewbricks/dev_mode/enable.
Dev Mode enables code that may take some extra time, however small, to execute and Dev Mode should therefore not be enabled in non-development environments. But its is highly recommended to enable it in development environments.
When Dev Mode is enabled, Fewbricks will:
Checks field names for max length. Due to WordPress’ database scheme, meta_key values in the _postmeta table can not exceed 255 characters. Since Fewbricks is prefixing the names that you give fields if the field is used in Bricks, it is possible, although unlikely, that the field name will ultimately end up exceeding that limit. If it does and Dev Mode is enabled, Fewbricks will trigger
wp_die()and tell you all about it.
Checks for duplicate keys. This is always done when adding a field to a field group, brick, repeater etc. In dev mode, Fewbricks performs an extra check after the array to send to ACF has been created and all field keys have been prefixed with parents.