Hi,
I do not see they pointed to any issue in the theme, your developer should be able handle the integration or provide us with an explanation of the issues they are facing.
They clearly state: They renamed the wishlist.php
template, forcing the premium version to look for it’s correct template.
For this to be added to the child theme the developer would likely need to add woocommerce/wishlist.php
to the child theme folder structure. As I do not have the plugin I cannot confirm this, but suspect it would be the first route to explore.
Thanks,
David.