Managed to finally reach 400fps+ in d2 benchmark.
Core 2 tuning in BIOS, SVM/IOMMU/TSME disabled.
Scalar x1, LLC Level 4.
Active cooling on the ram with a 90mm fan, 43C during TM5.
Passed Prime95 smallest to large FFT avx512.
Unfortunately I was not able to run 35/37 tPHYRDL on this board at 6200MHz, 6000/2200 runs stable but I had better results and lower latency with 6200/2167. I did try 6400/2133 with a higher tCL and different voltages but the IMC did not like it.
Also the tRCDWR is locked to whatever value tRCDRD is set to.
Either way I'm happy with the results and I can gladly call this my final tune for this setup!