Hide Categories for Some Users

I am developing a custom plugin that needs to dynamically filter the products displayed in the Ultimate Product Catalogue (UPC) based on the logged-in user’s settings. The goal is to restrict product visibility by category on a per-user basis.

I am using the [product-catalogue] shortcode on a standard WordPress page, but pre_get_posts does not seem to affect the query.

Could you provide any available hooks or filters that would allow an external plugin to:

1. Modify the UPC product query before it retrieves products?
2. Filter products by category dynamically?
3. Intercept or modify how the shortcode fetches products?

I would prefer to use existing hooks rather than modifying UPC directly. Any guidance on the best approach would be greatly appreciated.

The page I need help with: [log in to see the link]