Thanks for sharing, actually this very project inspired me to do it myself. It is an incredible resource when it comes to certain aspects of the database format!
Imho it has some deeper architectural issues though which I wanted to avoid in my implementation. I'm also using an entirely different tech stack I wanted to train myself in.
My implementation is not as feature complete as osxphotos but I'm sure I will be able to contribute back to the project with the occasional bug fix.