Thanks for reaching out! I managed to boot it. It booted installing a single module on the 3rd right slot closest to the processor, failed on 1st and 2nd. No idea why. The computer cycled like 3 times and then posted.When tried the Asus Sage, i also got a slow hart attack from no post for a while. The issue in my case was that eventhough it looked like the ram was seated fine it was not. I have placed quite a lot of rdimms in my life, also ddr5. But in the sage i had to do reseat some dimms 3 times. So yes easiest is first to reduce to 1 dimm, go gpu, try the 1 dimm taking it out and pitting it in and try again a couple of times. If no try one of the other rdimms.
Another thing is that the first time a particular memory configuration, the motherboard is training or calibrating itself or whatever and it can also take quite a lot of time. Looking like its stuck, but eventually, it can get out. So have some patience depending on the q-code it might be busy and you maybe need to wait 4 minutes or so and then maybe it continues. If you wait long enough, it will some times reset and try again. But maybe not always. On the sage there is also a flashback and reset cmos button, even on the back pannel so that it is convenient to reach. With my previous w790 ace, i could never post using any xmp profile with fury renagate pro 5600, the only settings that worked for me was almost Everything about memory on auto but set the frequency manually. Same as how i now use the micron server ram and overclock it. With any xmp even the 4800 setting it was not posting. so i never got any good cl timings. Now with micron server rdimms timings are 'automatically better' as stock but the same cl 40 as i had with the fury.
Good luck!
Thanks a lot.