Iwas thinking the relay idea is complicated after this all bearing in mind. But, in things like motherboards for PCs, car audio amps, they use larger capacitors on the switching lines to deliver smoother sine waves and to keep and maintain smooth DC power, as do caps have an effect to even out the sine waves in an A/C to D/C converter circuit, by varying steps of capacitor sizes. The smaller the cap, the quicker the discharge, and faster the wave falls before the next peak. So if the caps start large and then get smaller, they can make the output almost like a plateau sine wave. But that's just garble now.

I have an 8S 1/5 scale ESC. It has twin fans and is rated for 200amp continuous 34V x200A = 6,800 watts = 7HP that might get to the ground if you could ever pull 200A which means 6HP might be doable. The ESC itself sounds louder than a PC running at 5V on a BEC, and at 6V the fans are just loud! It's giant in an 8th scale buggy but Icould always use a sedan body on the buggy and extend the body mounts, get rid of the side chassis guards and outhang a carbon plate for bigger battery and ESC. It would need to be mounted where the motor is, and the motor swung up above the center differential, then you could fit an 8S pack under the body, and run a longer or fatter motor with larger pinion under or inside the body cab area since it would be the only room for the motor to swing to. Iwould have to bore the pinion out on a lathe and make a custom motor mount. But it could be done. Imight have to think about how many sacks of potatos Ican weigh the buggy in before it's considered overkill.