Wow, you have an awesome rig, with high density and only 5 GPUs with 562 Mhs
The memory temps are also awesome, but the only thing I would adjust in your rig is to decrease the fans speed
Maybe 80% will be enough to keep memories under 94º and this 20%less on rotation can help your fans lifespan
But you did a good job
And I noticed in the second picture you reduced the core clock on 3090 and "lost" some hashes, but the power draw decreased too
Agreed on fan speeds. I ran a 3090 at 100% fan speed for almost 1 year and one of the fans literally fell off. Card was still running good even with only 2 fans but I had to RMA the card to get the fan issue fixed.
A second 3090 was set with fan speeds of 75-80% and has not had issues. So I think 100% fan speed can cause the fans to fail faster.
Maybe it was a good trade-off to him since the price to replace a GPU fan is very cheap compared to VRAM. You can replace the GPU fan yourself, the high availability of GPU fans in the after-market. While you can only RMA the card when VRAM breaks or 3rd party GPU repair shop if the warranty expired. So the VRAM is under high priority even at the expense of the GPU fan, I think.