[P-hack]

Those are still constant mesh though. Dual clutch (or dual motor) is designed for "smoothness".

Back in the 1930's Chevy introduced constant mesh and a couple years later they came out with cone synchronizers.

Prior to that they used a much much simpler and more efficient "sliding mesh" gear engagement, where the teeth of the gears slid in and out of each other for engagement/disengagement and the rest of the gears are not rubbing against each other and their bearings all the time. Sliding mesh also had significantly fewer parts.

Good drivers (the ones who could rpm match manually) didn't have a problem with sliding mesh, but for everyone else it became known as a "crash box".

I don't know what the state of the art is, but it seems time for the efficiency of sliding mesh and electronic synchronization, especially if an electric motor is the input. The load (amps?) is actively set to zero, an actuator puts it in neutral, then rpm-matches (back EMF?) to the next gear, actively. It should be fast (though not air-shifter fast) and smooth, and the software can record the output torque prior to the shift and re-apply an appropriate torque immediately following the shift for smoothness, or just set most efficient torque for that rpm, because feeling when a car shifts isn't such a hardship that it should compromise efficiency, is it?

Dual clutch is obviously, to me anyway, a luxury with a significant number of extra parts compared to a single clutch, when transmissions don't even really need a clutch except to get rolling, or don't even need one at all with an electric motor.

They claimed 15%, and added a second motor that cannot be used with the first simultaneously, great, I know we can do better.