Apologies for your disappointment but I'll request to check the guide again please.
This guide does not force you to use a 3rd party plugin, but mentions about what's supported (see attached), including:
- Built-in WordPress export tool and the official WordPress Importer plugin
- WooCommerce built-in hidden link
Further down in the "Required plugins" section, there's no mention about using a 3rd party plugin.
In the section "Export Your Multilingual Content", it is mentioned about the different methods you (can) use:
If you’re using the built-in WooCommerce exporter, you can easily export all product data in all languages in one file.
Same goes for "Import Your Multilingual Content" section, which just explains that how you need to import, based on your export method, without emphasizing on any 3rd party plugin. However, it emphasizes on the use of "WPML Export and Import" plugin in the end:
Until you run WPML Export and Import, you’ll see all imported content under the default language and in Draft status. Learn more about how and why WPML Export and Import manages imported content visibility.
These both sections, even providing an example for "Built-in WooCommerce Exporter or Importer" (see attached).
Can you please explain or show where in this guide, it is misleading you to WP All Import? So I can check again.
Otherwise, I'd request to follow the guide with your CSV methods, try and let me know for any related issues. I'll try my best to further assist you on the matter.