For example if you choose hip then normally all bones waist up will be effected only when blend depth is set to 1. But if you use -1 will it be just the opposite?
Last time I tried it nope.
The way layering works is form that target weight upwards so what ever is layered below it will over write the depth. What you can do though is added a blend layer on the same blend per bone and decrease the blend weight.
Ahh ok thanks FrankieV!