Single variation product information is not updated when updating product in Complex IEF

This issue does require the patch from this issue being applied.

Steps to reproduce

1. Create a simple product type see commerce documentation
2. At admin/commerce/config/product-types/simple_product/edit/form-display, set the widget for the "Variations" field to "Single variation (Product information)"
3. Add a product entity reference field to any content type, referencing your simple product type. Set the widget to "Inline entity form - Complex". At admin/structure/types/manage/MY-CONTENT-TYPE/form-display I am checking both Allow users to add new product entities & Allow users to add existing product entities

Problem/Motivation

When editing existing products and product information in the IEF and clicking Update Product, changes to the product are saved, but changes to the product variation are not saved.

If you take the IEF out of the equation by navigate to the product itself product/*/edit, you can modify the nested variation and the Save button updates the variation as it should.

If you edit and update the product variation in the IEF widget on the node by leaving the widget open and saving the node, it updates the variation as it should.

Proposed resolution

Is there a way we can leverage the logic behind the Save button from the product/*/edit page inside the Complex IEF instead of the logic behind the Update Product button?