There have been multiple aftermarket modded batteries of various forms available for the Air 3 series (both of them), the max I have seen is up to 1 hour of actual, not claimed, flight time.
Update for everyone: the 140w charger I mentioned above works great. It was charging at around 90w for the hub, goes to about 110w if I add the remote. Still got about 30w headroom for other devices.
I am guessing the previous 90w charger does...
The charging rate and time is very slow using the USB side for all my hubs compared to using the usb-c to usb-c option on my Anker and well worth the price I paid for it, which I don't think was all that much compared to all the other things I've...