Imagine that is a wood texture with grain direction you want to control. Try orienting the grain by using 90 degrees in either of the rotation values - doesn’t work. Also, still no way to drive the blend with i.e. noise. And still no way to drive the normal lookup.
Here is the node setup I’m using to choose 4 different grain directions in a piece of furniture (1 mesh). While it uses the standard box mapping image node because I don’t need anything else for this one (complex enough already), I’m using collapsed UVs in UV space to select which empty I use to drive the box mapping. This is not triplanar mapping, just a way to get around how you can’t rotate the coordinates while an empty lookup will work just fine:
The image texture is the same (just a big seamless node to lookup from). Bump has been exaggerated here to better show grain direction.