Finally got it to run at 5200MHz! 42-42-42-82 timings on BIOS 3112 beta. Did a successful y-cruncher run, and I’m now running stressapptest on it to guarantee everything is ok.
My bandwidth improved a tiny little bit (from 48~50GB/s to 51~53GB/s) on Intel MLC, so I’d say this exercise was definitely now worth the time spent haha