there is an ongoing issue that you can’t do full-disk encryption when using UEFI. The linked bug is: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=213491
According to the history of the bug it is fixed as of February 24th. The newest install-images are from February 22nd. When can I expect to see install images that fix the problem?
I’d like to give TrueOS another try, since FreeBSD11-Stable was a PITA on my laptop. But FDE is a must for me (and my laptop won’t boot for whatever reason in legacy-mode not the image for the usb-stick).