I’m far from the first person to put together a Pi Zero USB hub. In fact, mine is loosely based on the open source design from @richardhawtorn, which was based on the design by @MakerBro.
The key difference is that I removed one of the USB A ports in exchange for a reduced footprint. As much as possible, I’d like my Pi Zero boards to have the same footprint. This design allows for a small USB WiFi adapter to be plugged in while remaining within the Pi Zero board outline.