Tailor entries : relation with different blueprints


I have a shop with different kind of products, each of them have it’s own blueprint cause the form is quite different between products.

I also have one blueprint to manage my categories.

All my different products belongs to my category with an “entries” form widget.
How can I create the inverse relation that would allow to link my category to all my different products.

The idea behind that is to be able in frontend to list all products of a specific category, with one simple request, or to count all products associated to a category

What would be the best way to do this ?

Thank you