Now that --convert-root btrfs is working (thanks so much for that!), I'm trying to create a separate data partition. sdmcryptfs says it'll take 117 minutes to save the rootfs (see attached photo.) It's been saving for 30 minutes, so I guess it's not kidding. What am I doing wrong?
I've also attached a script file created when I ran sdm --burn

sdm-citadel-burn-script.txt