the perfect position for the autoformers is full volume then they are simply a shunt element. The worst performing taps are in the 0 to -6dB range but they still have 100Khz+ bandwidth and what ringing there is is also above 100khz which is far enough outside the audio band that it doesn't bother me from a technical perspective. In any event the behavior of the autoformers at -3dB will far exceed that of any step up that you put in front of it and if just a slight amount of gain is needed (up to +6db) again the autoformers can be configured to seamlessly shift into step-up mode so you not only get 11 but possibly 12 on the dial. The important part here is that when you leave the "gain" mode you also leave the compromises incurred from that mode.
dave
dave