Normal Mask

Nogre

Hi, I've made a simple window generator in Substance Designer, I've also made a mask output and mapped for mask in Substance Painter. When I stamp it on a new layer with normal blending mode on the Normal Layer stack, it mask out on every channel except Normal. As you can see it works fine on the brush preview. Yes I can use a Aplha mask on the Brush but this is a parametric tool, the mask is also generated. Is there a way to use mask on the Normal channel?