I often luff in response to a gust. If the water is generally flat and you don’t need the power to drive through the waves I think you can get away with it for short periods. After all from the point of view of the sail there is no difference between a luffing and dropping the traveler.
On a related subject it is not appropriate to hold a steady course when a gust hits. The gust will cause the apparent wind to move aft so the correct response is to head up to compensate.