Can I use RGBA channels of a Photoshop layer as diffrent imputs for SBSAR?

Chat GPT  told me so  but I am not sure if it's true .

For example  I want to do height map erosion  by slope blur  in sbsar on top of smart object.   Can I have red channel as main  height input , the green as a slope  and blue as intensity ?  My guess SBSAR on top of a layer can't get an access to other layers  but perhaps can split RGBA into 4 grayscale ones inside a SBSAR, right?

 Should it work ?

 I just want some easy to use and convenient tool  with half decent manual drawing tools  that neither Designer nor Sampler  seems never going to have.    And this not so recent but still a novelty  SBSAR support in Photoshop  + chatGPT scripting  that started to actually work in Photoshop  vs  former two   makes  sort of great hope for  Photoshop again.