This is Bollinger Bands script with an option to choose three different moving averages. The simple moving average is the original settings used by Mr Bollinger. Exponential is a popular choice as it adds more value to the recent price movements. T3 is a lot faster at adapting to the recent price. Compared to exponential, it gives even more value to the recent prices and furthermore, it is smoother. I use it to polish my True Range scripts.
Another upgrade is the ability to have a different colour of the channel when the baseline moves up or down.
Back to calculation? Is it better to use T3 with Bollinger? My opinion is that it depends on the trader. Both of them give you slightly different information and it is essential to look at the historical behaviour and answer for yourself. Will I use T3 calculation? Well, I built this script to find out if I want to.