I’m embarrassed that I never thought of this. Sure enough, my library lends both e-books and audiobooks. It’s limited to 2-3 per month, but that’s more than I need anyway
This isn’t exactly what you asked for and might not even work, but look up xManager. It lets you install a modded version of Shittify with premium features on free accounts – maybe this limitation is something they also modded away?
Sounds like fetch with extra steps