A belated thanks for the reply. I found a slightly more optimized way to do this for some shaders: Effect Mask. For layer effects with a mask variant, the effect applies to the background, ie., all layers below it.
So, if you want to have an effect apply to all but one layer, you:
put Effect Mask on a blank layer right below the layer that is supposed to remain unaffected. Turn off layer transparency.
Add the effect individually to all layers above the unaffected layer.