I compared NVME and SATA here… for one plot the difference is surprisingly little, but for multiple plots it will be enormous due to the heavy overlapped I/O.
I think people forget how fast a 20gbps USB port can be, however, you have to pick the right controller interface chip or things get ugly real quick. The ASM2364 is what I use and can recommend:
Equipped with ORICO’s latest USB3.2 Gen2 main control chip ASM2364, which supports up to 20Gbps transmission bandwidth,uses PCIe 3.0 x4 interface with a theoretical bandwidth of 4GB/s, fully meets the bandwidth requirements of USB 3.2 20Gbps (2.5GB/s) and support NVMe