Improvement idea for the Portal BSDF Node

So the (relatively) recently introduced Portal BDSF node is super cool, but from what I've gathered it requires a whole bunch of math nodes to actually set up.

So whilst I don't know how difficult the implementation of my suggestion is, here's my idea on how that could be simplified: Add the option to specify a target object in the portal node.

Imagine a scene of like an indoor area that you want to be seen through a portal, you'd add a big plane in front of that scene which will be what you'll use as the target object. Let's call that the Window Object.

The dimensions of the object in question would determine the width and height of what the portal node needs to show, and the normal direction of the Window Object could determine the direction it needs to look at.

Doing it like this would make it lot easier to move the portal scene around, as instead of having to use very specific coordinates and then updating those coordinates if you want to move the portal, you could instead move the Window Object around to adjust what you see through the portal.

I think this would make it both easier to setup the portal node as well as making it more flexible (or at least easier).

Again I'm no coding expert in the slightest so perhaps implementing this is super easy or extremely near-impossible. I hope this idea will at least be taken into consideration though.