Might want to take a look at the older Anker LC40 as well:
https://www.amazon.com/gp/product/B01N6IHQZO

It’s a 3xAAA light that fits an 18650 cell with no issues. A 20700 or 21700 might fit as well, but I haven’t tried.
UI is fairly simple: high/low/strobe, but it does have mode memory if you keep it off for 10 seconds. On low, it draws 0.6A and delivers roughly 200 lm, so an 18650 cell should last about 5-6 hours.