I've manually run through the steps of casper's persistent partition creation on a local image. The partition creation operation, 'sfdisk --no-reread -q $DEVICE -a", properly creates the partition on the GPT, not on the MBR.
However, in the process it also "fixes" the protective MBR, removing the empty bootable partition.
We could adjust casper to recreate this MBR entry after creating the GPT partition.
I've manually run through the steps of casper's persistent partition creation on a local image. The partition creation operation, 'sfdisk --no-reread -q $DEVICE -a", properly creates the partition on the GPT, not on the MBR.
However, in the process it also "fixes" the protective MBR, removing the empty bootable partition.
We could adjust casper to recreate this MBR entry after creating the GPT partition.