This does go to show that developers need a function to get the field keys.
I propose something like: get_field_key( $field_group, $field_name ) ?
This way you can just give it the field group id: group_123456789
And the name of the field in the group.
The function would return the field key. Noone wants to hard code the field keys into the code because when you create the fields in another environment, the field keys can change on you.
