There are 4 channels in a block. A channel can be active in any of the 8 scenes. So for example take an AMP block in you preset, if channel 1 is used in scene 1,2,3,4,6,8 and chan 3 is used in 5,7 you would have the indicators showing "1=used, 2=free, 3=used, 4=free."Yes
But there are 8 scenes so why 4 indicators ?