Add Reference Dimensions to Faces on Bounding Box

Hello, I am trying to add PMI reference dimensions to the maximum dimensions of models in a dynamic way which works for as many geometry types as possible.

I have got it mostly working by using the bounding box to find points in the corner of models. As shown by the green highlight, I've associated the dimension with the points and the body.

https://drive.google.com/file/d/1KzEGZ74eh0yCXPhMXOmpvvSD58BLCZno/view?u...

However, I need to find a way of attaching the dimension to faces along the bounding box rather than arbitrary points. It should look like the image below.

https://drive.google.com/file/d/1Pnz3dP29lNvW3fNZFHUvNcxhY_5vZE6_/view?u...

Is it possible to find faces on the bounding box which could be added to the associativity in a dimension builder using a journal?