I have been trying to use parented objects in a DOP network. For instance I have a bounds object that I would like to use but is parented to a null. I originally thought that I could reference the bounds object and have it update in the DOPS network as it was transformed by it's parent. However that doesn't seem the case. I'll attach the files if you need to see what I mean. Any tips on this would be great.

bbox() and centroid() functions are sampling geometry in object space so you will not get any obj level transforms

but you can easily create new unparented geo, and object merge your bounds object inside with Into This Object option
you will get geometry from bounds object in world space which you can then use for bbox() and centroid()

this will setup your container size on the first frame, if you want it to happen continuously, you will need to use Gas Resize Fluid Dynamic DOP as well

and obviously you will not get your smoke box rotated according to bounds object rotation