Randomx is dependant on latency which is why cache performance is more important than DRAM speed. There's no way
increasing DRAM performance, even by 25%, will increase the hashrate by the same amount. Huge pages, on the other
hand, can have that much of an effect by reducing effective memory latency with fewer TLB lookups.
I stand by my advice. There's nothing wrong with faster DRAM, it's just low on the priority list in this case.
If it's bottlenecked by RAM like 3900X/3950X then performance increase from lower latency RAM is almost 1:1. Slower CPUs like 6 and 8 core Ryzens are less affected but they also benefit from low latency RAM.