I spent a couple of years working on this as a hobby and, yeah, book metadata is difficult to explain just how irregular it actually is. It might actually be worse than people names.

That being said, the reason I was working on this was because I wanted a simple and effective way to get alerted to new books published by authors I want to track, can this work for that?

As a feature within our app, probably Q2/Q3 this year; we want to finish backfilling historical books before turning actual notifications on

As an API for you to query yourself for free, not for a while (but on the long-term roadmap!)