My original prototypes didn't have that part (330uF capacitor) included, but when testing with a high-impedance power source the voltage tended to sag and cause problems so I added some extra buffering. If you're using a direct connection to a decent hub, it's basically just insurance.

Kano's driver is very unlikely to work natively with the BM1398. The chips enumerate themselves on the bus with a distinct ID per generation, which the driver uses to distinguish which chip (and how many of them) it's talking to. It won't recognize the 1398's response and so won't initialize it for use.

Temperature sensing using the innards of the BM1397 also won't work natively. Bitmain implemented a register set that communicates with an external temp sensor over I2C using some otherwise unneeded pins, but this has to be built into the driver protocol. It is true that the two temp-sense-diode pins could be interfaced to any temp sensor chip and handled externally.

I've looked into using USBC PD for higher power on a device, but at the time there was no real provision for running both PD and data, nor were there any reasonable hubs that would do the 20V spec. Additionally, providing a higher voltage into the device would tend to *decrease* your conversion efficiency, unless you used something like a forward converter with a transformer to help balance out the duty cycle. The problem isn't the power into the main regulator, it's the power out. 400mV 40A bucks are a rare breed. I've looked into this and it's sorta possible but I have something like eleven design projects already in the pipeline so I'm probably not gonna do it anytime soon.