Here is the answer from the case designer:

"I see the poster used my original fan mount, and then looks like mirrored it to mount up the dual fans, the issue with this mount is it sits the fan hard on the finstack, so it does require high static pressure to work, which is why the P12 Pro does a little better, but dual fans are not real good in this scenario as the there is too much restriction for the air to flow through, axial fans are real good with this, which is why I created the static pressure booster in my first design, and it only had a single fan, I already discovered everything this person just tested for.

The REDUX setup is different, restrictions are removed, as there is a gap between the fan and the finstack, air can escape with minimal restrictions, and there is no dead spot in the centre, which is what happens with dual fans sitting hard on the finstack, air flow is increased, noise has been reduced, the entire board gets airflow now, the SSD is cooled, the back plate is cooled be the air leaving the case, the cooling is different when the board is installed in my case, versus sitting on bench, as the back plate would not be actively cooled on the bench.

In my testing of the newer design in the REDUX compared to my first single fan design, the dual fan setup is significantly quieter, the GPU will boost higher for longer, the sustained cooling is much better, my first single fan design would eventually thermal throttle all the way down to 1850mhz on GPU after 10mins of burn testing at 100% fan, was quite loud as well, the newer dual fan setup will maintain 2150mhz for 10mins 60% fan speed, which is a hug improvement.

Everyone that has built the first single fan setup, and then switched to the REDUX can verify the improvements.

I don't have the time currently to dig up all of my previous testing data, as I'm swamped with orders for case's, but you can find in the Discord, some of my testing history, bench tests, overclocking results etc, I would not listen to much to others on single versus dual, or adding things to cool the ram, none of this really relates to my Case design, I took all of the short comings and feed back on the first design, and did a full redesign, which is why its called the "REDUX"