As of the latest release (21), you can simply install microG on regular LOS and no longer need to install LineageOS for microG since it now includes the necessary signature spoofing support.
refreeze
If you don't need the GPIO then buy a small form factor office PC like a Dell Optiplex Micro or a Lenovo/HP equivalent. They cost about the same on the used market, are more performant without the ARM headache and use only marginally more power (maybe 5-10w more at idle).
Ubuntu -> Arch -> Debian (stable) -> Fedora Silverblue -> NixOS
I'm curious, why do you use LVM with BTRFS and not just use BTRFS built in subvolumes?
btrfs snapshots are still useful on immutable distros to recover accidentally deleted data.
You will hate Ansible if you are coming from Nix. I went the other way and Nix is 1000x cleaner.
Being able to actually reverse changes is trivial in Nix, but can be a headache in Ansible. Not to mention the advantages of writing in an actual language and not yaml full of template hacks. I personally don't see much future for tools like Ansible, there is considerable inertia working in its favor right now and it is absolutely true that it is widely used, but the future of configuration management is for sure more aligned with how Nix works.
Similar to my scheme:
laptop = "laptop"
nas = "nas"
router = "router"
Then if there are more than one in each category I use nas-0, nas-1, etc.
Wow, to each their own I guess... Is this satire?
Bangle.js watch is probably the closest thing, but I'm not sure how good it is compared to Garmin.
I quite like Fastmail. It's a bit expensive but the service is very reliable and they have a well established reputation. You can create masked emails using their domain or your own from the web interface.