Ive you use Node Wrangler you can already see it happening in the material preview. There is banding happening, this affects the displacement. Im not really into nodes so i hardly know enough to fix this. My gues the values are wrong. Displacement works with black and white and values in between. But your adding green into it, im not sure if the green is seen as color or as black/white channel by itself. Perhaps convert it to black/white than input it in the multiply value?
PS i check the github page, he notes him self “This addon doesnt support shape keys”. Hmm is it reallu usefull than?
Ps have you tried using a displacement modifier and than using those vertex groups as input. I think it looks a bit better than. What i dont get is when you devide the channels. why it shows also red in the green?!