We are running a multilingual WordPress website with MultilingualPress and WooCommerce.
We have made some adjustments by adding a Custom Post Type which is hooked up to the Woo Product Categories.
We are able to rewrite the URL structure for the main website. However, these URL also have to be rewritten/translated for the subsites.
I've provided a clean test website ready to build up on. With only 1 custom plugin activated due to the CPTs.
If you have read the above and you have experience with URL rewriting please contact me!