Samples per order and of the same sample stop a cart from filling up with samples.
Samples per customer in a number of days, matched by account and billing email, stops repeat free orders.
Limits are checked when a sample is added, in the cart and again at checkout, in the Checkout block and the classic checkout.
Samples never take from the full product stock. With Count sample stock on, each product or variation can have its own sample count. It goes down when the order is placed and back up if the order is cancelled. At 0 the button hides.
Samples and full products can share a cart, or samples can be ordered on their own.
