Comment 7 for bug 1911440

Installed using subiquity focal iso, and btrfs filesystem for the whole drive.

Enabled compression via force-compress=lzo mount option in fstab.

Rerun btrfs defrag tool to recurrsievely compress /boot with lzo.

Upgraded to new grub, and dpkg-reconfigure it just in case.

Rebooted. in grub console, check package version

grub> echo $package_version
2.04-1ubuntu26.8

Completed boot just fine.

Thus I think grub2 in focal with btrfs lzo compression still boots fine.