I'm using Xiaomi 20,000 mAh power bank, and passthrough works great. Mine only supports 18W out, when I have my 30W charger plugged in, the power bank charges a

I'm using Xiaomi 20,000 mAh power bank, and passthrough works great. Mine only supports 18W out, when I have my 30W charger plugged in, the power bank charges as well.