Live filters from imported sbsar

So we could have our own custom filter that we could specify certain group as inputs .   Turning height  into normal map   for example, or doing edge detect from certain layer beneath.    Or  doing image displacement based  on some some rgb  values of other layer. RG for vector and B for distance. 
All this is working in Substance Painter  . Why not do it same way in Photoshop which I so much prefer to Painter or Sampler for tillable textures.      Especially after  pattern preview emerged.