This does not work?
Page Type is equal to Parent Page (has children)
I already know that it’s not likely that custom location rules will be added for custom post types, at least not by the developer. So it the above does not work your only real option is to create a custom location rule.
And I do have an example that will do something similar here https://github.com/Hube2/acf-filters-and-functions/blob/master/page-nth-level-location-rule.php that I’m sure can be made to work with a few tweaks.
