ZFSBootMenu EFI Variables are not suppoted

Preface: I’m a fairly technical hobbyist who has been using Linux for years as my primary personal system. I have a couple Raspberry Pis and a couple computers I saved from a landfill as family members no longer needed them. This is my first time trying out ZFS

I am trying to get ZFS as my root partition on an old iMac (Mid 2011). It boots with various live USBs including Ventoy (what the live debian installer is on), and used grub2.

But I am getting errors starting with creating the fstab. I think it’s set correctly, it has

UUID="myuuid" /boot/efi vfat defaults 0 0

I think it’s just throwing an error when I re-run the command to set it.

When I try to configure the EFI boot entries with the command from ZFSBootMenu Debian Guide I get the following

root@debian:sys# mount -t efivarfs efivarfs /sys/firmware/efi/efivars
mount:   /sys/firmware/efi/efivars: mount point does not exist
  dmesg(1) may have more information after failed mount system call 

And if I keep going, and install efibootmgr, I get messages about my system not supporting EFI variables.

When I take the Ventoy flash drive out, it doesn’t find any drive to boot from When I hold option/alt to have it let me choose the boot device it doesn’t bring up the menu, instead I get a folder icon with a questionmark. The boot device menu describes the Ventoy drive as EFI Boot.
Any one know how to get efivars set properly?
Thanks!

Edit to add: I tried the openzfs instructions before I remembered Jim and Allan talking about zfs boot menu. It didn’t leave me with a system that would boot either.

For me, I have always had EFI variables not supported errors when the system has booted off MBR. When I have rebooted via EFI (either by changing bios settings or using a different boot usb), then the problem was resolved.