One of the unfortunate things about the Raspberry Pi Zero is that the second micro usb is power only. For this type of configuration I encourage all to check out the Allwinner ARM-based SoCs and boards built from friendlyelec. With the NanoPi Neo I was able to enable USB ethernet gadget mode on its micro-usb and then have it host and power another device on its USB-A (for me a mobile phone). In my use case the laptop powered both the NanoPi and charging the mobile device all from USB power while also acting a an ethernet packet router from the mobile device back to the laptop all over USB on its own subnet.
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