This is interesting. As I just mentioned to @jtp10181. I was actually using an old 1TB 2.5" SATA SSD in a USB 3.0 caddy, formatted to ext3. Speed is not a major issue, so I don't really *need* NVMe (and I suspect USB 3.0 would be the bottleneck, anyway).
However, as part of the reset, I've...