You might be right. I was thinking of it in terms of a traditional distro, as I use vanilla Debian where my advice would apply and yours probably wouldn't.
From what I do know, though, I guess /etc would be part of the writable roots overlaid onto the immutable image, so it would make sense if the immutable image was sort of the initramfs and was read when root was mounted or something. Your command is probably the correct one for immutable systems.
I'd argue that sometime around late season 2, it went beyond being a mere "love letter" and just became a masterpiece of its own. I feel like seasons 3 and 4 contain episodes that are in the top tiers of any Trek. The only episode I think that can be considered among the worst in the franchise is "A Mathematically Perfect Redemption". For the rest of them, though, I feel like they develop relationships very well in a way that rivals even DS9.