Very interesting Antonio. Bollinger Bands are useful when volatility is low. Hubert and
John Carter has an custom indictor called the TTM Squeeze which is a combination of bollinger bands and keltner channels. When the bollinger bands are inside the ketlner channel, it gives of a first signal. When the bollinger bands then move out of the ketlner channel the indicator will fire of a squeeze signal in either direction.
The concept of this is to capture any breakout moves that occur when volatility rises. I have never used this indicator but the concept does make alot of sense.