I am not an ACF developer. Just the guy that patrols these forums. The developers don’t monitor these forums. To submit a feature request you need to contact them directly.
When I duplicate a field group on multiple sites I do this by either creating the field group in the theme in the acf-json folder or exporting and importing the field group, or even building common field groups into a plugin.
When I do imports where I will not have this standardization then I use WP All Import Pro with the ACF add on that deals with updating the fields properly.
I realize that it is too late for your current situation. But if you will have standardized fields on multiple sites then these should be done so that they are the same field names and keys. But I would look into a tool like WP all import that will do this rather than trying to roll your own.
