A recent Delaware supreme court holding might motivate contract drafters to define the term for themselves

If your client is going to contractually commit to using "commercially rea­son­able ef­forts" to do something — but expects that obligation to require some­thing less than “all reasonable efforts” — then you’ll want to make the client's expectation clear in the contract language itself. Otherwise, if a court were to follow a recent trend in Delaware case law, the court might judge your client's performance against an all-reasonable-efforts standard.