For the USB C issue... USB C requires something called power delivery "pd" to negotiate the voltage and current to be supplied. My best guess is the resistors are not there in the charger to "fool" the pd into supplying the 5V. When using a USB C to USB A adapter, the USB A part has a resistor (around 56kohms) on the current line to trick the device giving power to it to give power, or if using a dumb power supply to trick your pd enabled device into charging on that dumb device. So... If you are using a USB C to USB C, just power the charger off your power supply and you can access the folder. If you are using USB C to A it should work, so long as the adapter has the resistor in it. That said, I would not power it externally while connecting to USB A. I don't have confidence that they built in protection for that use.
Inline discharging. I have the .6 firmware, the inline discharging did nothing extra, I was still only able to get 40W discharging. However, during my testing I removed the resistor bank while it was still discharging. I pressed a button on the charger and thought I stopped the discharge cycle but it didn't. And when I removed the resistor the charger kept trying to discharge through the "infinite resistance" so when I plugged it back it it shot up to 30A, and of course the PID controller brought it back down again. But, the charger is capable, they just have to design the firmware right.