Emboss FX working from selected channel grayscale values, not just layer mask only.

I currently have to do it in Affinity Photo  because it has live filter  supporting this . But I would very much prefer to use  Photoshop  with its content aware move anf fill tools .   Mostly just because it supports scripts and automation.  Otherwize APhoto  gets gradually quite competitive.   It's shame really Photoshop stopped to develop other new features  and focused entirely on AI  which yet  have to show any value in my pipeline   ( CG and gamedev ) 

I need this feature to sort of visualize  height images. To fix photogrammetry  produced height map   for example. Remove artifacts and too noisey areas with help of content aware fill for example.   But height images  themselves are very hard to read  untill you drop them in 3d rendering soft  like Blender.   Its an option too  but  would be nice to just have a bevel option works on red or any   image channel .    Since it's work only from a layer transparency currently I had to do  first a group where  I make dark pixels transparent  with "blend if" dialog  and still have to make another group  to set zero fill and have bevel&embos with it.     

With often hi res  height images  photogrammetry provides it's not very convenient to  do smart object + emboss filter either.   It's not real time  and takes time to save big image each time you do a small nudge .      And sometimes you just need real time  responce when compositing pieces .   

Could you post screenshots (including all pertinent Panels) to clarify in which situations this would be called for? 

Also ones to illustrate the Layer Stack you are using as a work-around now. 

How many additional Smart Object instances and Groups are you introducing at current?