Here is a another summary if the first writeup is difficult to understand:
Basically what I need is a way to change the name input of a custom field depending on the post that is being edited.
So if we are editing a post that has a URL like this:
http://inboundsoon.dev/wp-admin/post.php?post=95897&action=edit&variation=2
Then I need to modify the ACF saved name input to have -2 on the end of it.
And when the same page loads it needs to detect that it needs to populate custom field values from the values stored with -2 in the name key.