Can't upgrade 13.3->13.4, kernel hangs at launch, "Loader needs to be updated" with 13.4 loader.efi

I have a server currently running 13.3.  I'm unable to upgrade it to 
13.4 because when I try to boot the upgraded boot environment, the 
loader hangs where it would normally launch the kernel.  The graphical 
boot menu shows the "Loader needs to be updated" warning despite using 
the loader.efi from 13.4.

My setup is EFI boot to a ZFS root (zpool mirror) using boot 
environments.  Steps:

1. Use bectl to create a 13.4 BE
2. Mount, chroot, freebsd-upgrade 13.3->13.4 as of 24 Jan 2025
3. mount EFI partitions
4. copy loader.efi from 13.4 to both EFI partitions
5. unmount the aforementioned
6. bectl activate -t 13.4
7. shutdown -r now
8. Observe loader hang trying to launch the 13.4 kernel
9. Reset, observe BE safely return to 13.3

Watching the console, the pre-graphical part goes by too quickly for me 
to read, but I do catch a big box made of asterisks that looks like the 
one shown in a forum thread[1] about this issue.  When I get to the 
graphical boot menu, it has the "Loader needs to be updated" warning 
just above the autoboot countdown.

The loader loads the kernel and modules, shows EFI framebuffer 
information, then where it normally would launch the kernel, it 
hangs[2].  Hard reset and the system happily boots back into 13.3 (many 
gratitudes to those who created Boot Environments).

I've tried recreating the 13.4 BE thinking I broke something, but it's 
repeatable.  If I try to boot 13.4, I get the loader update warning and 
a hung system.  Reboot back to 13.3, update warning disappears, kernel 
boots without issue.

I also verified that the loader in each EFI partition is the one from 13.4:

# bectl mount 13.4 /tmp/BE13.4
Successfully mounted 13.4 at /tmp/BE13.4
# mount /boot/efi0
# mount /boot/efi1
# ls -l /boot/loader.efi /tmp/BE13.4/boot/loader.efi 
/boot/efi0/efi/freebsd/loader.efi /boot/efi1/efi/freebsd/loader.efi
-r-xr-xr-x  1 root  wheel  868352 Jan 24 04:47 
/boot/efi0/efi/freebsd/loader.efi*
-r-xr-xr-x  1 root  wheel  868352 Jan 24 04:47 
/boot/efi1/efi/freebsd/loader.efi*
-r-xr-xr-x  2 root  wheel  906752 Jun 27  2024 /boot/loader.efi*
-r-xr-xr-x  2 root  wheel  868352 Jan 24 04:47 /tmp/BE13.4/boot/loader.efi*

and confirmed those are the only loaders configured:

# efibootmgr -v
Boot to FW : false
BootCurrent: 0000
Timeout    : 10 seconds
BootOrder  : 0000, 0001, 0004, 0014
+Boot0000* FreeBSD-disk0 
HD(2,GPT,fa3c15e1-1bdb-11ee-a300-ac1f6b6b9e1c,0x28,0x32000)/File(\efi\freebsd\loader.efi)
                             nvd1p2:/efi/freebsd/loader.efi (null)
  Boot0001* FreeBSD-disk1 
HD(2,GPT,f6e68146-1bdb-11ee-a300-ac1f6b6b9e1c,0x28,0x32000)/File(\efi\freebsd\loader.efi)
                             nvd0p2:/efi/freebsd/loader.efi (null)
  Boot0004* UEFI: Built-in EFI Shell 
VenMedia(5023b95c-db26-429b-a648-bd47664c8012)
  Boot0014  Hard Drive BBS(HD,,0x0)


I saw PR/282001 related to this, and I also saw some of the earlier 
mailing list about it with the RC versions.  But this is a release 
version of 13.4, so I figured it would be fixed already.

What am I missing?

1: 
https://forums.freebsd.org/threads/loader-needs-to-be-updated-14-stable.94857/
2: https://pasteboard.co/8gC1qfLY6zmL.png