Pleased to know it worked, Jon. But please don't ask me why...
I guess that whatever it is that causes the artifact/ghost is not copied (at lease by SuperDuper) when the clone is made- much as the Emergency Startup is not copied to the clone.
Of course, I now wonder if a clone made by CCC enjoys the same success.
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