Gads! Not having a bootable backup is a bit (a big bit) of a game changer for me, e.g., I may delay updating to High Sierra until Carbon Copy Cloner (or SD!) gets theses issues resolved.

And I fear DiskWarrior will also have issues with APFS.

<rant>

Harv
27" i7 iMac (10.13.6), iPhone Xs Max (12.1)

Those who can make you believe absurdities can make you commit atrocities. ~Voltaire