When a product has broad usage profiles how do you create one for a test protocol. Do you select the easiest? Obviously not because there is risk of a high failure rate from poor evaluation. Do you select the hardest use-case? You could but there is the risk you spend too much time and money making the product overly robust for most of your customers.
In these cases where test time is limited and only a single use case can be tested I create a “Composite” use-case. It captures many of the different types of stresses from the full list of use-cases but keeps an accumulated stress on the design that represents at least 98% of the customers.