Thanks @dutchshader, that is getting there! I just don't know if this is asking too much from Affinity products. The attached file from another forum post did it, but I have no idea how that works....the Origami product is perfect, but that requires Illustrator as well as the Origami license ($100 plus Adobe which is $600/yr...or the main boxshot product which is $200)
Honestly, the attached file does what I need, but I don't know how to re-create it with my own template, with regions in the main artboard spilling over mostly properly to other sides. I could completely do this with images, and then apply them to 3D models (I am in the mechanical engineering world), but that does not allow live updates.
Thanks @firstdefence for the pointer to Boxshot, I many end up going that route.
box_symbol_isometric.afdesign