Clearly I'm confused:
I. After Carbon Copy Cloner copies an APFS volume to an HFS+ volume, what happens were one to copy that volume back to the original APFS volume. Would it remain APFS or will it revert to being an HFS+ volume?
2. Or, to put it another way: After Carbon Copy Cloner copies an APFS volume to an HFS+ volume, does the newly copied volume remain HFS+ or does it become APFS?
If I read correctly cloning a APFS volume to an HFS+ drive does
NOT change the volume structure if the target drive
ie. the target drive remains HFS+. Neither does it clone the two or three other hidden volumes present on the APFS drive at this time. That will take a significant amount of additional engineering to accomplish. The CCC clone is file by file not sector by sector.
Other than the Recovery Volume, I have no idea what the function of the other hidden volumes on an APFS drive are and no idea what the effect of cloning back from an HFS+ Drive to an APFS volume would do.
My question to you is why not format both the source and target volumes APFS or clone to a sparseimage file formatted APFS (realizing the sparseimage would not be bootable)? Why do you want to cling to an HFS+ formatted drive or volume? There is a lot of new functionality in APFS that High Sierra and its successors will take advantage of that are simply not possible on an HFS+ volume.
