we need to set a maximum number of purchases (4) per user, for a certain product category. Let me explain: in our website there are 4 purchase kits per category, in which the user can make a maximum of 4 total purchases. He can make a purchase for each product or buy a single kit 4 times. After 4 purchases, we would like to block the possibility to purchase the product. we have put the products in the same catogory, then within the category we set the maximum number of 4.
Then in WooCommerce > Settings > Maximum Products per User > Limits we have enabled Per category tag option. Do we have to set other parameters? Or does it work properly this way?
Your setup looks correct if you are trying to limit the product quantities per category. I would highly recommend though, that you make a test purchase to ensure the limits are working correctly as per your requirement. You can use an offline payment method for your test purchases.