Node or formula based interface for dynamicly generating "smart" masks

[kirk23]

Like a mask that is  being calculated on the fly  by group A  composited red channel  subtracted from a sum of lighter blending  of layer B red channel and layerC green channel.          If nodes are too much of an issue let it be a math formula field  in  a special window.

Yeah. I can do all this by layers , groups and linking.   But to be honest the layer stack with layers is getting  so complicated  I couldn't understand a thing  in my own files.

Would it be just so much easier if we could just see a single mask layer  with  like 2-3  input button  next to layers name   where we could select layers  involved in dynamic calculation .       Would be cool if we could save it as live filter or smart mask   or whatever.   

  The whole  Layer stack  would be so much easier  to read , manage  and  elegant  without necessity to scroll through gazillion of groups inside groups  with pixel linking etc .

it even doesn't have to be  100% on the fly .  Some update hotkey command  would be ok  .  per  selected layer and beneath  or globally for a whole document  in case APHOTO WOULD STRUGGLE TO CALCULATE IT all IN HI RES.