FreeBSD is the only one providing native support for efibootmgr(8) in base (linked relative and very well written FBSD manpage). Any derivative should have it too.
Providing the fact TrueOS and GhostBSD are the only FreeBSD distribution providing a graphical installer and a pre-configured desktop, and that TrueOS only supports ZFS root (Lumina DE is entirely designed around the ZFS paradigm, with boot envs, snapshots, compression, dedup and wast else), your choice is pretty much limited to GhostBSD, which among the other things, uses Grub2 as default bootloader/bootmanager, by bypassing FBSD's loader() and calling the kernel directly wihout chainloading.
By the way, what's your problem with ZFS? I confess I prefer UFS2 too on desktop,being simpler and more lightweight, but surely ZFS has its own good pros to be picked out