* Custom Key Settings AF/MF Button = AF ON
* AF w/Shutter = OFF
You will AF on the AF/MF button
Shutter using the Shutter Button
This will also allow you to Focus Recompose Dynamically on a Face.
OR , AF (let go of the AF/MF button) then Recompose and wait to shutter
note: because I do have "AF ON" on my AF/MF switch button , and Eye AF on the AEL button ...
I "do" notice that Eye AF does make the AF a bit slower while it looks for Eyes , when there is none.
And on the same target AF ON locks on AF fast. ...
this might be the reason why #Sony separated the two AF and did not provide a Option for "Both" ,
at least for now - Until they work out the Software to make this Faster. :)