You can swap the side panel which the stand attaches to from the PSU side, to the GPU side, and then use the case vertically with the GPU at the bottom, which allows the PSU to breathe freely. I did notice a slight increase in overall system temps like this, as the heat from the GPU rises into the rest of the system, but the power supply fan was able to run at a much lower and quieter speed.
There just isn’t a large enough gap between this stand, and the panel to which it attaches. It really is the Achilles heel of the Fractal Ridge. Of course if Achilles had just worn some reinforced boots, the problem could have been solved. The same is true with the Fractal Ridge.
After seeing how much worse the performance was when positioned horizontally, I decided to remove the included feet and simply position the case on top of four stereo component feet. This allowed for a much larger area of airflow beneath the chassis, and improved performance dramatically in the gaming test (meaning that it could actually complete the 30 minute run).
This test was made with the case positioned as Fractal shows in the manual, with the PSU and CPU cooler fans facing downward. My thought was that even with the more open airflow allowed by using the four component feet; this still relied entirely on the PSU and CPU fans to pull air from beneath the chassis, so I tried one more experiment.
While still using the four component feet, I flipped the Ridge over, positioning the GPU intake at the bottom, and the CPU and PSU at the top. This was absolutely the right decision as the temperatures in this horizontal position actually bettered the vertical results with less noise and heat buildup. During all of this I also made some attempts at utilizing the space for the three 80mm fans, but they actually didn’t make a huge difference to the GPU, and had a negative impact on the CPU temps (some more of those strange fluid dynamics)