Hi Z-man,
I am not sure what lead feet means...
However, the Gaincard definitely doesn't play as loud as an Aragon, ARC, Nakamichi Stasis, or any other amp I had except for maybe the Aleph, but it does control the bass very well. So, I wouldn't say the Gaincard needed help with the 103/4. After all, it is a 91db efficient speaker.
And, ont he contrary, the 103/4 actually needs to be away from walls to produce feasible bass, that is, before I tried the Gaincard. With the Gaincard, I can push the speakers all the way back and remove its elevations. The bass is still better than with the other amps. But, the highs greatly improved more and more as I get the speaker closer to the wall.
So, maybe the Gaincard has better synergy with the KEF and the newly acquired Bogdan silver cables I am using now. The Tannoys I was using didn't fare as well with this set up. I think, perhaps, Tannoys just like copper cables.