^
That may have been the case for a very simple refinery. In a more complex refinery some of the naphtha stream is blended into gasoline directly but most goes to a downstream unit (the reformer) and makes pretty high octane blending stock. There is some adjustment that can be made trading off octane for volume. I've already exhausted my recollection of all this so maybe someone else can chime in.
That may have been the case for a very simple refinery. In a more complex refinery some of the naphtha stream is blended into gasoline directly but most goes to a downstream unit (the reformer) and makes pretty high octane blending stock. There is some adjustment that can be made trading off octane for volume. I've already exhausted my recollection of all this so maybe someone else can chime in.