Author here, thank you for the kind words! My goal is always to write the thing I would've wanted to have when I started out.
Do you prototype all this on a breadboard before making the PCB and picking specific parts? I'd be curious to hear more about your process. I feel like I always need to test everything I build on a breadboard first since I inevitably miss some small detail if I go straight to schematic + PCB design.
If I'm pretty familiar with everything, I generally dive into a rough PCB layout and debug from there. If I absolutely can't get anything to work, I'll go back to the drawing board and possibly do some little breakouts, for example: https://twitter.com/theavalkyrie/status/1457845661370568709
Edit: for this specific project I did make breakouts for testing the MOSFETs and solenoid drivers. I'm glad I did, since I was able to try out a couple of different options for each: https://twitter.com/theavalkyrie/status/1550878465876004865
Do you have any books you recommend on electronics? I feel I understand the basics, like what various components do in isolation, but would love to level up and understand circuit design like how you are approaching it here
I can recommend Practical Electronics for Inventors as a solid base of projects to experiment with and learn from. If you want to learn how to improve circuits and optimize for specific behaviors, there is a wealth of information in manufacturer application notes. A lot of the protection circuitry used in my article follows advice found in application notes.
One thing I wanted to add - I recommend placing a large-ish cap (22u) when using ferrite bead\inductor, as you can get ringing/oscillation otherwise.