While I have little trouble believing they can pull off a 6C charging rate to get that ~10 minutes... at least as far as what the batteries can take... I mean there are plenty of high C rate batteries out there that can do that... especially for the first 80% of the batteries SoC.... they of course aren't the best in kWh per kg ... or per $ cost per kwh... but 6C is doable ... at least as far as the batteries go... if the pack is designed for it.
The catch for this type of opportunity charging ... is the same catch that has always been there.... where are you going to get access to that much Electrical power?
if they have about ~ as much battery capacity as the Telsa does at ~50 kWh ... that would mean to charge at 6C would need a 300kW + electrical interface.... considering 200 amp service at your house is less than 25kw ... 300kW all in one plug... is a crazy amount of electrical power.
Sure electrical sub-stations deal with this kind of power and more all the time.... but I don't know how they would do this safely for the consumer... and even if they did... it would be very few places you could get it.
But I suppose just by offering it... it gives a solution to the common complaint about taking many hours to fully recharge under more normal load levels... so they tac it on a solution ... and just don't bother to say... where you will actually have access to an electrical plug that will dish out that much power.
How bulky and heavy would that 300+kW electrical plug / cord be?