Passing along the answer (to my problem) from another site; the definitive reply came from Bill G4WJS.
"Hi Jerry,
"Settings->Radio->Split Operating->Rig" is preferred, if you have problems with it then try "Fake It".
One or the other should work.
They essentially do the same thing but "Rig" uses two VFOs on your rig for a smoother transition between Rx, Tx, and back.
For example some Yaesu rigs have limited Rx bandwidth in USB-DATA mode,
but you should not give up the Tx benefits of USB-DATA mode if you rig is like that,
instead use "Rig" split mode, set "Mode" to "None",
then you can set USB on the Rx VFO and USB-DATA on the Tx VFO.
You will need to set the rig modes manually.
73 Bill G4WJS."
73 jerry km3k
