Set Scaling Grip Parameters - Scale Lock Dynamic Component Adjusting the Boundaries

I just finished making a dynamic historically accurate double paned wooden window. It works great. I decided to complete the full window assembly and added in the interior wooden trim and stone sill, since I have to add these anytime I put a window into a structure anyways. As far as how the function within the model itself, they work great, but when I added the extra parts the overall outer boundaries from which the scale tool lets you grab from got bigger and now I don’t know how to get the rough opening of the window to line up with the rough opening of the building exterior.

Here’s what the process was like before I added the extra parts:

And here’s what it’s like once I added the sill and trim:

Is there a way for me to customize where I want the scale tool to pull from?

My hope is to be able to insert and scale the entire window assembly in one move, as opposed to having to create a separate dynamic component for the trim and sill, which would be a pain in the butt to line up properly, and insert as a second step.

I’d like to figure out a way for me to anchor the window assembly @ the yellow star in the diagram below and drag the scale grip from the red star. In other words, be able to scale from the window jamb itself and let the trim and stone sill follow:

With how many windows a typical house has, it would really be a time saver.

Here’s the model of the window assembly itself, which has been uploaded to the 3D warehouse and is available for public download if anyone wants to take a look: