In an ideal system, acceleration makes no difference since the final kinetic energy of the moving vehicle is the same. However, real-world cars are *not* ideal, and there are energy losses in all parts of the system, including friction in the moving parts (axles, tires etc) and electrical losses in the power system (batteries, inverters, motors), pretty much all of these ending up as heat. How *much* heat is complex, since the losses are related both to the time taken to get up to speed (which favor higher acceleration) and the instantaneous power being applied causing greater losses in the motors etc (which favor lower acceleration). This means the optimal power curve to minimize the energy needed to reach a certain speed is complex, and not necessarily as short as possible (that is, minimal energy is *not* automatically equated to minimum time, i.e. maximum acceleration).

I don't know what the optimal curves are, and I suspect they are very much related to the target speed. But I *highly* doubt they correspond to maximum acceleration.

As for regen, that also is complex and depends on the methods by which the car torques the motors to modulate the regen rate.