Thank you for the warm welcome @BortLicensePlate, @JamesRobot, @Bearcat-Doug, @DoctorEncore, and @Scrobins!
@Sumez, I read that nesdev wiki article about vblank/nmi and found it very enlightening. I was definitely of the "do it now" mindset and will keep in mind to save vblank time for drawing with as little logic as necessary. The fact that NMI code will happen during main was also something I had not thought about. I can't say I absorbed everything I read, though. I'm sure I'll be referring back to that page for some time.
I don't expect anyone to look at these or let me know if I've misunderstood anything, but here are the notes I have from following Nerdy Nights, so far.
Sorry for the oily stains, sometimes life just leaves some bacon on your notes.
https://www.dropbox.com/sh/h3yon7ti0b8loj0/AACGIyRBtfNki0B9gqyPxlZ5a?dl=0