The case design would slot in the otherwise independent NUC formfactor, providing power and airflow, housing the (e)GPU and other cards, and re-enabling all the benefits of cramming things in the 5.25" drive bays on the front of your PC.

I got really frustrated recently after running out of space on my desk for all the cabling and clutter that used to live inside my computer. I had to build a rack to house new equipment to replace what was in a PIII ATX tower, and I find myself slowly losing ground to the copious adapters and peripherals I need to replicate the utility of formerly self-contained systems.