bands should be moved by a fixed point value  instead of deviations.

1st band= vwap + for example 50 points

2st band= vwap + for example 70 points

I agree. Heatmap should allow you to set Min and Max color ranges for the Market Depth Historical Graph. Like this for example. Now volfix heatmap is useless for me. Please add this update.

Thank you for replay. My explanations on pictures.