The trouble with that is to a certain extent we're just kicking the can down the road. Modern Tesla vehicles have more range than older ones, yet people still charge modern ones to 100% for various reasons.

The idea here is to leverage their incredibly fast rate of charge and short term nature to reduce time spent Supercharging. Very roughly speaking, you can charge from 0-90% in an hour, but to go from 90-100% can take almost another hour.

If you could get the car to 90% and then very rapidly charge the capacitors with the remaining 10% that trickles in, you get the car off the charger faster. In theory you could almost double the number of cars you could serve at that station.