The werewolf curse acts similar to a Circadian Rhythm in that it no one can remain in one form or the other indefinitely after being cursed. The longer one resists the harsher the outburst when they eventually do turn. On the flip side one who abuses the power too much will find themselves spent and unable to turn when they might have been counting on needing the power most.
What the Bannermen practice is a method of tapping into the power of wolf only up to such a point where they have enhanced musculature and bone structures. They are constantly on the verge of a full transformation but balance it in such a way that they minimize the potential for burn out. It is an extremely difficult technique to master taking decades to perfect.
They always risk pushing themselves too far and going into full wolf mode. Which given how they are constantly walking a knifes edge the burn out will be much longer than a typical person abusing their power. The burnout time / magnitude varies by bloodline and age. The older a person gets the more reduced their periods of burn out making them exceptionally dangerous especially given how much larger the elder Wolves get.
White Wolf doesn't have a very big role in Babette's Tale, but I though it would be appropriate to have him make an appearance in Vampire's wrap around segment