IMHO, because the Rocket needs so little throttle for normal speed street riding, the MAP and throttle position sensors are too "coarse grained" to adequately control AFR, especially when un-restricted and the timing tables are changed accordingly. The difference between 2% and 8% in throttle positions in the Rocket is vastly different than in a 4cyl Nissan automobile, which to equal the desired response is probably close to a 25% change in the Nissan. Add to that a lack of a plenum, which adds volume reducing the pressure fluctuations between an individual cylinder's valve opening events and then between cylinders' valve events. The sensor and ECU have more time to measure and respond to averaged pressures in a plenum than the real time pressure changes in a single TB runner. Hence, any deviation from normal in the Rocket's TPS's operational characteristics is felt immediately by the rider and shows up in AFR deviation, where as in the Nissan a similar change isn't felt at all.
Sometimes, I ride at steady slow speeds one gear higher than I care to just to reduce the sensitive, even twitchy throttle response (in part due to very rapid AFR changes.) One of these days, time permitting, I am going to add an adjustable volume accumulator between Map sensor and the three-way hose tee. By buffering pulses between cylinders, the Delta P processed by the ECU will be reduced. It will be an interesting exercise.