Some links from a research on large inflatable pools:
A nice pictorial summary of some different inflatable pool products "for adults": https://www.pinterest.com/pin/464011567839765743/
The main thing I learned was to search for brand H2OGO on eBay. Interestingly this search no longer produces links for the big deep rectangular one that we got; everything is back to normal now and inflatable pools are for kids again: https://www.ebay.com/sch/i.html?_from=R40&_nkw=h2ogo+pool&_sacat=0&rt=nc&LH_PrefLoc=1
It seems that Amazon no longer sells the big hexagon pool that was available in 2020 either: https://www.amazon.com/s?k=h2ogo+hexagon+family+pool&crid=1IHGRFU4F6Y6O&sprefix=h2o+go+hexagon%2Caps%2C183
