Currently we need at least 4 GB of RAM for the Live system when the booted sytem in theory only needs <1. This is because everything gets copied into RAM at boot time.

I would like to remove the need for so much RAM, e.g., by loop-mounting system.uzip, and merging it with a tmpfs using unionfs, and then chrooting into that.

FuryBSD had a unionfs setup but it was more involved: https://github.com/furybsd/furybsd-livecd/tree/union-tar-nochroot

I'd like the simple version (loop-mount read-only filesystem, overlay it with tmpfs usion unionfs, chroot into that). If it doesn't work, then collaborate with unionfs kernel devs (who maintains unionfs? @mjguzik, @cemeyer?) to make it work.