@lsscpp Is generally right.
It’s kinda doable in the custom build. Can’t say if it would work as it should without testing it out.
SSR has fallback to cubemap built in that I’ve disabled in the custom build I made (not released) to help the nodegroup get closer to the intended effect. It would be possible to enable it (like it is on default blender, but the nodegroup is not working as it should due to fallback being subtracted from the area with SSR), but I don’t think there’s a way to easily do that without interferring with other specular reflections as the addon is only in specular space (should be in diffuse).
Since I’m relying on a single node to provide both SSR and Diffuse bounce in case of principled shader then I need a way to mix it better with the cubemap that’s left on the base shader. It might be possible by doing something like the ShaderToRGB node does, if it could be modified to include SSR too (might not be technically possible) and use the fac from that to mix it with the base shader cubemap (or in other words - mix shader for only specular). That would give enough flexibilty to improve the interaction with base shader cubemaps.
If that would work just parenting a cubemap with autobake to camera is in similar vein. Of couse it would just be a cubemap still with no actual tracing done in that space.
This is all speculation
I could add the fallback back in, but as I said before it then needs a lot more flexibility than it currently has to mix specular with other nodes (even the base version does to not just add to, but replace fallback).