The interesting bit (to me) is the algorithm. They automatically detect how slow each available swap space is, and how sensitive a workload is to memory latency

The interesting bit (to me) is the algorithm. They automatically detect how slow each available swap space is, and how sensitive a workload is to memory latency and then swap memory pages into compressed dram or nvme storage in an optimal way. So yes, it's "just swap space" but highly optimized.