Im still waiting for someone to show data to confirm that sizing a capacitor properly does not store and return power to a motor. But I’ll say two things as it relates to this concept and your scenario. you would need allot of the right capacitors for them to add anything to the available power. secondly it would not work in a constant acceleration application. it would only work in continuous acceleration and deceleration applications which is not drag racing.
so then what you have left is a capacitor acting somewhat like a resistor that is frequency dependent. imagine that your motor is designed to work best with when it gets a pulse of electricity that looks like a trapezoid. the trapezoid is the shape created by lots of little pulses to create the shape. it has an angle on the slope up and an angle on the slope down. in the middle it should be flat. if instead that motor gets something that looks like a square it doesnt have the right angle up and down. from the motors perspective anything that sits outside the shape it was designed for (trapezoid) is turned into heat. thats not a problem if you dont have a heat problem. but anything that sits outside the ideal waveform can do more than create heat. If that is something interesting im sure I can help but at this point im pretty sure you will get more answers on that whether you like it or not. but the cleaner the power is through the esc and to the motor the more power your motor can deliver.