16GB optanes with an ordinary SSD interface are pretty widespread in China and DIYers do use them for swap/pagefile. The problem is that they take up a whole M.2 or NVMe slot with the corresponding number of PCIe lanes…

These drives generally come from budget laptops where the optane is originally used as the system disk. Not a good idea anyways and computer shops usually swap them out. You pay about 28 CNY for 16 GB, which is 2x the average SSD price-per-gig.