I'm assuming that the fundamental architecture of the new ECU is quite different than what the teams used to have. Based on the slight scraps of info coming out, it appears that the only input to the engine throttle is the driver's foot. My assumption is that previous teams' versions the driver's foot commanded inputs, and the UCE adjusted throttle, spark, etc. to suit parameters. That way, if a driver downshifted, the ECU would command the throttle to adjust the engine RPM to a specific RPM, and shifted gears. Now, with the new system, when a driver downshifts his foot is responsible for finding the correct RPM as the transmission selects a new gear.
I've got to brush up on my control theory, but we need a better understanding of the fundamental differences between the systems once used, and the new, standardized ECU.
A proud Canadian, and yes, HOCKEY is our game.