Try 0.33b? I have tried implementing a checking solution for the grub part. That said, 0.32 only supported ext3 disks, nothing higher. 0.33 should support ext4 at least.
Please bare in mind, though, that we don’t know every possibly outcome of every imaging job. We are doing this all on our free time. So making this a “Perfect” solution is the goal, but we need far more testing and assistance/coding experience to make that a possibility.