I don’t have a direct answer to your question, but one limitation on the speed of the Nucleus Rev A and B is the SSDs they use, which you can upgrade. See this thread: Tested the Nucleus factory SSD vs latest Samsung 980 Pro
I run ROCK on 6i5 and 11i3 NUCs with Samsung NVMe SSDs (6k albums / 115k tracks). The user experience is snappy on both.