Importing Variation Categories

Does anyone know if it’s possible to import variation (not variable) product categories?

I’m using the inbuilt product importer.

When I import one product with N variations, the variations inherit the parent categories even if I explicitly set the variation categories in the CSV. (the variation categories in the CSV are ignored)

I have a plugin that shows/hides variations as per the categories they’re assigned to, which is why I ask. Given the variations are a post_type there must be something in the WC code forcing them to use their parent’s categories. Even if someone can point me in the right direction I can see what’s going on in the code (FYI I’m a developer).

Thanks v much!