The #NetBSD Project offers a live image for AMD64 that includes X11 and features persistence.
Why does nobody ever talk about this?
I put this image on a USB drive, booted it, logged in as root (no password needed), created a user account, started X, configured the network, and everything was still there after a reboot.
https://cdn.netbsd.org/pub/NetBSD/images/11.0/NetBSD-11.0-amd64-live.img.gz
@passthejoe Mileages may vary; I installed NetBSD 11 on a VM last week to see if it's workable, and it decidedly did not allow root login without having set a password. No doubt I did something wrong... but that does underline NetBSD's user experience is not quite consistent yet.