Sure, patch your software, but you can keep accumulated feature requests on a separate branch. Then, as time goes on, decide whether you should rather monetize on an updated and more feature rich version, or just push updates and make people happy. I'd say there is more money in the first option, while the second makes me feel better. It's the developer's choice. Check https://www.holdemmanager.com/ how they do it.

For OP's kind of software, I'd say one time license purchase would be the most user friendly. So yeah, sell it like people did in the good old days, before the cancer that is SaaS took over the world.