With boot.initrd.systemd.enable = true; and console.earlySetup = true;, I still have to type my LUKS passphrase in qwerty. The logs say this:

systemd-udevd[176]: vtcon0: Process '/nix/store/09iq39jicajnvf3305176rj1pghgyn0i-systemd-stage-1-250.4/lib/systemd/systemd-vconsole-setup' failed with exit code 1.

but not much else apparently.

The vconsole is set up fine by the time I get a login prompt.