I have some fairly complex logic that sets the title of a product display node in hook_node_submit().

The products attached to that node will update their titles automatically the next time the user edits those via inline entity form. Good. But I also need them to update their titles when the parent product display node is saved with a changed title.

Where the heck is the code that commerce kickstart 2 is using to automatically set product titles? If I can find it I should be able to use that to update the product titles.

Note I am not looking for a rules-based solution here, thanks.