It is awesome to have in-place editing working for material content children, whether material-based or texture-based. Thanks for that.
However, from a user standpoint I think the material preview should remain focused on the current top-level material, rather than switching to preview a texture, or worse, a conceptually non-material content that is necessarily implemented as a material.
The idea being, if I am editing a material, and select a texture, I don’t prefer to see the texture previewed in 2D, but would rather continue to see my material, which of course will also reflect any changes I am making to the texture.
In the case of a non-material content, this is even more desirable. For example, we have a topcoat layer type of node that can be placed over various material substrates, and it would be far preferable, when selecting it to edit its attributes, for the top-level material to continue to be shown. In other cases, the content simply has no visual representation on its own.
Perhaps the last point suggests a need for there to be a fourth “utility” type of content, in addition to the existing texture/environment/material ones, but even in that case, this wish about keeping the top-level material in the preview would still stand.