That is still nine or ten hours a day when the dog is left to it's own devices to relieve boredom and cope with situations it has no control over - weather, people and other animals passing by etc.

Training class is a very good idea - if only to ensure the dog is socialising and that it has some mental excersise.
I would still be concerned that the dog is alone for too long and is able to break out of the kennel.

Why not suggest your friend looks into a dog sitting service or maybe employ a neighbour to walk and visit the dog during the day - if only for the dog's safety if nothing else?