I know, I know—there are so many static site generators. Still, I just wasn't satisfied with the available options. None seemed to support cache-busting and minification without a lot of setup; and many seemed to have significant requirements for building themes, many of which didn't make sense for my use-cases.
Yagss uses Jinja style templating, has a built-in cache-busting mechanism, minifies output by default, and has a few other features that aim to make it easy to throw together a simple website without having to figure out too much config.
I hope that yagss might be useful to a couple other people out there with similar requirements for their projects.