I have heard of this before, in the link I posted, they say to keep adjusting the S-AFC to a lower and lower setting until the ECU cannot compensate for the lean settings of the S-AFC. Then you richen or lean from this point to your desired settings. However, if the ECU is reset it must not be driven hard until it has pushed itself to the extent of its limits again.
Opinions on our cars?

-Steve

 

The ECU would return a CEL if it could no longer adjust to correct the rich/lean condition.

once you adjusted it back into "proper" with the S-AFC, the ECU would again start making adjustments.

 

the ECU will modify the fuel trim over-time.
the s-afc works my modifing the fuel map on a quick burst basis.

So your regular driving, the ecu learns to adapt to normal conditions, and when you raise it into the "high-throttle range" it'll change the fuel map. which normally would be WOT.

So i'm guessing that unless you run the s-afc fuel map all the time, you should still see the gains from the fuel map.